How to check if array has same values java. Check if every elements in array is of same value.

How to check if array has same values java some(v => v < 0); The key is the object we want, and the value is determined as follows: If the key never existed, we have a list with at most one element, which is the same as the key; If the key has existed prior, we have a list with at least one element, which is the same as the key. So any array in java is full and Question is to check if array is full or not. If you instantiate a non-primitive type (array in your case), it won't be null. I want to add another number to index 6. So, it will start comparing itself to itself, which has the same name, but if you remove it, both (or the same) will be removed. this doesn't quite satisfy me . equals"). Checking If Values in Array Are Different Java. On each iteration of the array of objects: if output doesn't already have a property key that matches the name of the current object create one by assigning it zero. compare 2 arraylist in vb. How to find the largest value from an array in Java? 0. Hot Network Questions Is their any predefined function in Java such that I can check if all the elements in an array are different? Or do I have to write a function from scratch to find it? I have a String array below: Check if every elements in array is of same value. " you can sort the array and then check for each new element if the next two elements are the same. asList(yourArray) so you don't need to populate one-by-one. g. Is there any efficient way for this. Here's how it's laid out. but the for-loop doesn't seem to work. int[] numbers = new int[3]; In this case, the space is allocated & each of the element has a default value I really miss a simple indexOf and contains in java. So, loop from index - 0, 2, 4, 6, then loop from index - 1, 3, 5, 7, @polygenelubricants: Unless specified otherwise "are those the same" means equals() in Java. Looking like: "Shoppinglist-fruit", "Shoppinglist-dinner" So how can i check if the name of the object inside the second list is also in one of the objects of the first list. I want to add the value of num and delete duplicate name if the name if equals. Is the first element of this one the same as the first Glad I could help! If you wanted to edit the JSON object you could just replace it with the corresponding id. The concept you're looking for is the difference between shallow equals ("==") and deep equals (". Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog Better to use a HashSet than an ArrayList when you are checking for existence of a value. Check out the API and in particular the java. * But it works. name that happens to be all of the elements . Viewed 2k times -1 . I know we can iterate over the Map and use the return boolean of map. So if the array was {2,2,4,7,7}, it should return true because it has two 2s and two 7s. The other condition is that the value the user enters The above method stores a CommissionedEmployee object to the CE array, I tried to use the for-loop to loop through the array and check if the i position of the array is the same as the parameter. Hot Network Questions Isomorphism-invariance and categorical properties in Set Basically, what I want to do is check two integers against a given value, therefore, classically what you would do is something like this: //just to get some values to check int a, b; a = (int)(Math. equals() method defined in Java Arrays class. (Your method may First of all, in this loop, it starts checking from the same index. x-tag 125 154 166 125 125 222 125 In above list,it has value 125 for 4 time I have the value 125 from another and i can check whether list having 125 or not. If you have better code for larger arrays, please share. The filter() method creates a new array with all elements that pass the test implemented by the provided function. value array I can't place it if the index contains any other object. So possible workarounds are: Using Predicate. It's definitelly worth look at Arrays. So I tried this code: I have array list with value like . If b is true, that means that at least one element is null and array is not full. Viewed 8k times 3 . 13. Then increment that property's value with the current amount. I'm trying to write a method that will accept an array and find any equal elements that appear next to each other and return a count for the greatest number of occurances. I am supposed to check it with a parameter. length I am from . out. Java check if Map values are the same. Check for values with same key in a list of key-value pairs. lang. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Java creates an array with capacity count of references to the Candy instances initializing array with the nulls. getString("COLUMN_NAME")); if is perfectly fine, there is nothing unprofessional about it. Secondly, the break takes you to the line strings++, when you want to skip that line. Method above throws runtime exception in case of different length of arrays. If the value is in the array, pull the collection, add the next index and finish the iteration. keys(obj), since even 'numerical' keys are strings). So just choose one as a reference and compare this chosen value to all other values. For each row if you find a value that is different from 0 you will set that position in the corresponding array to one. Using Binary Search Method: In Binary Search Method, search a sorted array by repeatedly dividing the search interval in half. you could I'm going to assume that your data structure is this: ArrayList<ArrayList<String>> matrix = new ArrayList<>() Your team objects though seem to be well defined and would benefit from not being a string so when you parse them in, parse them a s a real object. length; i++) { if Use a map,store value as key and occurence as value. Since the length of the array list is different what you can do is: 1. A HashMap may have duplicate values (but not duplicate keys), but I want to display a value only once. In don't see why this should be put in question here. nextInt("Insert the number of rows of the matrix"); columns = Teclado. I checked similar queries down here but they addressed the question with answers containing ArrayList and HashMap. arr = [10, 10, 10] then print out: "no winner" How do i check if all elements in a arrayList is equal? Could use a Set as an intermediary placeholder to find the duplicates as Bozho suggested. to check whether the list of arrays has same value. double[] testArray = new double[10]; // will generate a random numbers from 1-20, too lazy to write the code I want to make a search loop to check if any values are being repeated. That part works fine. If (and only if) you can easily extract the key of the map from the elements then you would be better off looping through your List and for each element do map. containsValue(value). if the last for fails you should change i1 to start from the second occurrence of the same value and so on. This method first converts the array to a java. Exception in thread "main" java. If the value of the search key is less than the item in the Basically, you are looping through the matrix and checking for the value. I am not familiar with them and trying to answer it with an array. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Here's an example that uses Integer instead of a date to make it easier to read but the principal is the same. compile("Joe|Jasha"); boolean found = false; for (String s : person boolean sameStepShape(int[] a, int[] b) that checks whether the two parameter arrays a and b are the same overall shape in that every position i has the same classification (upstep, downstep or plateau) in both arrays. If there is a collision, map a key to an array of collided values, and check to see if any of the array values match according to the equality function. If two arrays have the same length, and contain the exact same primitive values and references, it's If you have a lot of big arrays, it may be better performance-wise to implement your own hash/equality functions and use a Map as a HashMap. Once you have split the input into words and put them into a string array, put the first word,as a key, into the Hashmap and 1 as it's value. 7. An array with {1,1,1,2,2,3,3,3,3,5,6,7} would return a value of four. getString("DATA_TYPE"); // database values System. Override the equals methods in the BarcodeItem and check whatever parameters that makes them the same item. Intersection of the Arraylists in VB. split(" "); //loop over the array; if any value isnt an integer return false. I want to create an array of size n with the same value at every index in the array. I need the method to return true if the two arrays contain the same values even if that are . check[] = {1,1,1 you won't have this problem because the size of the array will be deduced by the number of elements in the I suggest to use Array#filter with the target array and return true (later also the value) if the element of array1 with the same index is equal to the search value. 5 (third person has 5 nums) 13 43 67 89 146 Right now, I'm trying to find the odd and even numbers of an array. The method is supposed to return true if it can find two different pairs of matching int values. currentarr is a shuffled version of arroriginal which the user HashTable{ 450 => Array{ 1, 5 }, 300 => Array{ 2 }, 150 => Array{ 3, 4, 6 } } where the key is coordination value, and the value is an array of turtles that have it. Arrays. And that too, without looping (performance measurement). Say I have an array of 100 elements and I want a certain range of indices to have a certain value. toList(array). The value is then stored in the array. Check If value appears twice in array. at this point, the method does not works because it need an instance of Set. Objects can either be added to it or have a property modified. Modified 11 years ago. I have already a for loop which checks if the value is null and if it is then add the student. ArrayIndexOutOfBoundsException: 18 Is there any other way to check the array index if it has a value or empty? My code: I know absolutely zilch about Java programming, but I've thought of this problem more generally for some time and I think I have a workable solution that is generalizable if you know a priori all the values that can be contained in the array. size !== arr. Then again a loop, from 2nd index to maximum possible with a step of 2, to check for opposite sign, but all same. For examples let's take array [1,2,3,4]. size() == 1; While this code is pretty compact, I would favor the more straightforward solution of iterating. and it will give yes or no output. Compare map key with a list of strings. prototype. I realize this is very simple but I cannot get this to work: Your code should work - but will not be particularly efficient. Easiest option, works in almost all cases, except that null!==undefined but they both are converted to JSON By far the easiest approach is using a simple for/of loop. I'm making the following assumptions: The arrays only contain numbers. Edit If unique elements are taken from both the arrays and if they appear to be same, then also array should be equal. For int, the default is 0, zero. The Java Arrays class contains lot of pre-defined or built-in methods to solve array related problems like sorting, searching, copying and Now i wanna print all items in the first list, except if there's a same object in the second list with the same name (Shoppinglist-drinks). My program is supposed to make sure each value the user enters is between 10-100. Check if array of objects containg sub-array all have the same values. start = s; this. Get the jar file from here. Here's a little bit of my code: check same value between two Array android. equal(int[], int[]), but it will just hide 3rd loop. – Answer by @Peter Lawrey fails in cases where the array has largest value is the last element. How to store a set of unique integer arrays in java. 4 (second person has 4 nums) 13 22 43 146. Java provides auto-boxing for automatically converting int values into Integer objects. Set. I am tryng to print out "no winner" only when all elements in my arrayList is the same. Share. Two or more users could have the same password. includes(undefined); // true (You don't need to write undefined, but this makes it more clear what's happening. Filling the structure: for each turtle: get coord value do we have it as a key yet? no: create coord. Commented Feb I put numbers of three people in one arraylist and in the case if three people have the same number then overall occurrences++; this is my algorithm but it is not working for this case!! 5 (first person has 5 nums) 13 20 22 43 146. If the current element is not equal to the value, you must set the value you are looking for to the current element, and set counter to 1, to count in the current element which is already set or "found". ) The problem with passing a 2-star argument is that is not a 2D array, and the compiler can't tell what its In this example element are not same position in both array list so return false. ) with all values equal: for-loop:18ms, set:32ms, stream:85ms, so the Set solution is not the worst; the accepted stream solution You could try using Collections now renames to Guava. check 2 == 2. Here's a sample removeDuplicates() implementation. What's the best way to do this in Java? For example, if n is 5 and the value is the boolean false, the array should be: = [false, false, false, false, false] @AmirPashazadeh The original question was 'the fastest way to', not 'the most elegant way to'. But since you are in a learning stage, I will rather stick with your approach here. Thanks Let's see how your algorithm works: an array of unique values: [1, 2, 3] check 1 == 1. You could present your elements as an array, so if you've more than two items to check, the condition will still short and the same, using . if they don't reset the counter and go to the next element You could start with sorting the array, then start checking the i with i+1, if are equal then you increment counter otherwise you set him to 0, you repeat "How do I check if the String contains a particular word present in the Array?" is the same thing as Is there an element in the array, for which the input string contains this element. */ public class Demo { public static boolean isAllSame(int An array of primitive values has no empty slots. One idea I have is to create two 1D arrays, one with the length and the other with the height of your 2D array and fill them with zeros. Yes, if you create two strings like: String a = "Hello"; String b = "Hello"; They will be the exact same object. I have tried this code but it doesnt se You can write a method like this (using java. I'm learning about Java array and got stuck on this problem. It is 4x4 and has 16 values which all go up 1 at a time. Modified 11 years, 3 months ago. check 2 == 1. Get the lengh of the array with the largest size I would use a hashtable with in key takes the element of the array (here string) and in value an Integer. And the relative performance when all elements are not equal will vary based on the index of the filter has two parameters, one foir the callback, which is here a prototype function of Set, has which checks a value against a set. Note: If this is not possible print -1. Good idea to check what's more performant here. length == 0) { return false; for (int i = 1; i < array. but the next time at that index, my index will still be index = 0 and now I am re-initializing that element in the You have two options using java. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company How to check if array of objects has same value for same key? 0. It Method 2: Converting array to a List Another method to check if an array contains an element is by using a list. To compare two arrays we will use Arrays. size() is definitely not helpful here. – So I have a an array List that looks like this: <id,value,id,value,>and I should find all the elements with the same id and add together there respected values into a result array list (value always comes after the id). reflect. the second parameter is thisArg, where you can hand over an object, which is used as this in the callback. deepEquals() method comes under the Arrays class in Java. If the value is the same, return true (you've found a duplicate). The elements may be in a different order or at different How to Check if Java Array Contains a Value? There are many ways to check if a Java array contains a specific value. So I should find whether the Map has duplicate values. JavaScript: Check if all arrays contain same value? 0. a2: The Given an array arr[] of N elements, the task is to check whether the array have all same (identical) elements or not without using the loop. You don't care about the order of the elements; rearranging the arrays is OK. with a new list I'm going to start at index = 0 and my list. length to check if the array has duplicates. You store a reference to the same object in every loop. Ask Question Asked 11 years, 3 months ago. All slots hold an element with a default value for that data type. Create an output object, and then iterate over the array. Another option can be new Set(arr). I'm writing this just to know something more about '==' operator in java. ArrayList<String> u = new ArrayList<String>(); ArrayList<String> p = new ArrayList<String>(); These arrays are populated from a file of the following format: username password Like so; The reason your code fails is that you are trying to find a match for a name in the elements of result1 Array to result2. How could I check if there are two (or more) same name value in array? I do not need a counter, just setting some variable if array values are not unique. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company All values are the same is equivalent to All values are equal to any selected value. private List<SomeType hi guys i want to ask something if i want to check whether the array has a 4 consecutive elements or not like this This code iterates through checking if the next element is the same as the current element, and if so, adds one to the count. Firstly, array indices start at 0, not 1. I suggest putting your array checking logic in a separate method that returns a boolean. every() method like: myArray. )), so cannot use . I know my findEvens() and findOdds() methods are messed up because they keep giving me off values whenever I try to print the final result. How to check same value in same position without using for loop I want to expected result this if. check 2 == 3. public static int[][] transpose(int[][] A) { int m = A. Run a loop to check every value Though the position of elements are different but the elements are same. e. I find it kind of funny that such a simple deduction needs a special name!) Here is an easy way to do it: ArrayList list = new ArrayList(Arrays. I've created a two-dimensional array that contains 5 rows and 5 columns. check to see if 3 values in array are consecutive? 0. Annoyingly you cannot use continue on its own as this applies to the inner loop. * @throws IllegalArgumentException if any of the arguments is not an array or if the lengths of the arrays are not equal. You have two options: Have a unique Id for each type and check if it's the same Id. Arrays; /** * Don't take it serious. When you run the contains() method, it sees that the list does indeed contain an object equal to the one you provided (in this case they both represent a value of 5), and so it returns true. For this I have to check numList[6] contains a value or not. integers[ 2 ] = 42 ; // Auto-boxing. Thank you in advanced. I want to know whether any method exists to find duplicate values Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Run a loop, from first index to maximum possible with a step of 2, to check for same sign. Hot Network Questions You're on the right track: assertArrayEquals should work. – akarnokd. then go through the list doing something like this : (array); } /** * This method process the string array to find the number of occurrences of * each string element * * @param strArray * array containing string elements */ private This works by checking if the final Set has the same number of entries as the array. ] Option 1. The OP has indicated that array modifications should be avoided. If not, the count is reset for the next chain. For example an array with the int values of {1,2,3,4,4,4,5,6} would return a value of 3. some which will return true or false if an item in the array matches the given condition. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Now I want to test if one of the arrays contain a certain value. One of the requirements is to check if a certain column has a value or not. – ljleb. List and then Below is a simple example that uses Arrays. next()) { resultTemp = new String[2]; resultTemp[0] = rs. contains("silly")) { // my array has silly ! Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog I'm trying to create a function which checks to see if any two indexes in the array have the same value. list. If not, then there must have been a duplicate. anyMatch(input::contains); Given two arrays A[] and B[] of the same length, the task is to find the minimum number of steps required to make all the elements of the array equal by replacing the element with the difference of the corresponding element from array B. This way, you can return true as soon as you find a repeated number (return I am reading a csv file. Parameters: a: The first int[] array to be compared. contains() might have to iterate the whole list to find the instance you are looking for. Example ; I have an array called numList and it contains some values. Hot Network If I remember correctly, Arrays. I think the fastest approach is the brute force one, i. From the javadocs ,"this method is appropriate for use with nested arrays of arbitrary depth. Then with two simple for-loops you can read all the values in your 2D array. Any help is greatly appreciated! "non-existent By mode, I am checking if the array has duplicates. So in your case, a key will be a word of the string you have split and value will be it's count. do{ rows = Teclado. However, java/c# are more/less same. String[] words = { "example", "hello world" }; String input = "a whole bunch of words"; Arrays. Improve this answer. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company If you really want to know how many duplicates of a given value you have, you need to iterate through the entire array. As of ES2016, you should use Array. Yes, you can write those in 1 minute; but I still went over to StackOverflow expecting to find them somewhere in the JDK. Commented Jun 10, 2012 at 22:46. Arrays class to transform the I have a list and I want to be sure that it has at least one not null element. It returns the index of the value you are search for, or a negative value. Looping through two arrays to check if equal. (This is actually an instance of the Pigeonhole Principle. check 1 == 3. Also you do not need to write your own function for array compare, but use Arrays. First you can write a tranpose method. containsKey(getKey(elem)), this will be much faster. User enters the number for the element(s) that is wanted to be fetched from the array list. log(containOnly([1, 2, 3], [2,1,2,3,5])); I have trouble with printing out "no winner" at the right value. First of all, I would suggest using a HashSet since it would take care of all repetition checking for you. public class Team { Set<String> teamMembers = new HashSet() public boolean equals( Object o ) { return I have a school task where you are supposed to make a method that checks if a already made array has 2 numbers of the same value. Every row will take at most n(n+1)/2 comparisions which isn't wonderful. For a direct solution with explicit looping, do this: You can do this by separating the methods. Java: Checking equality of arrays (order doesn't matter) 1. You can test it yourself by doing You are directly comparing the string with a character which needs to be changed and look at the below steps: (1) Iterate each row of the char array (2) Get the string from list (3) Now Iterate across the columns of the array and compare with each character in the string (4) At each step, I have added validations to check if they are comparable in length and break, if not, There are 2 problems with your code. I need to check if all values in a map are equal. ). However, I am getting . You can use Hashmap to do that. Instead you want to continue the outer loop so that the line strings++ is not executed. binarySearch(x,array) provided if your array is sorted. I want to check if the array has changed at all (could be element(s) added or simply just have one object have a key changed), and then update the Credit for the isInteger check goes to Determine if a String is an Integer in Java. e. This is the initialisation of the array: Product[] product = new Product[3]; I found similar questions here Checking if long is in array and here Look if an array has an specified object. would a given gene tend to always be replicated in the same direction? So here is my array. equals"), which is related to the difference between reference equality ("==") and object equality (". Examples: Input: A[] = Basically my mate has been saying that I could make my code shorter by using a different way of checking if an int array contains an int, although he won't tell me what it is :P. equals(a, b) iterates over both arrays at the same time and checks whether a[0] == b[0], a[1] == b[1], and on and on, but a[0] might differ from b[1]. Javascript check if any elements in array are equal. You need to compare every element in the list with every element in the map. Modified 6 years, 6 months ago. if it always checks the same array for common elements with many other different arrays - you will apparently want to convert it into a Set just once and store it in a constant outside of the function How I would want the code to work is that the user has to enter integers to an array list until the value -1 is entered. For example, if I try to find the odds of {1,5,8,3,10}, it gives me {5,3,0}. String studentList[] = {Paul, null, null}; Now I wanna add another student but make sure before if the student is not already in there. Oh, and you're accessing a non-existing array element, array[9] when i=8. size() == 0 too. I have a method to perform this task but would like to use a library or native methods. If none of the values are the same, increment your index and do the same for the next row. contains(x) which does exactly you are doing right now. end = e; } @Override public String toString() { Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog This function will return true if an array contains specified values. Correct me if my logic is wrong, but assuming an array of size 3, and the variable 'i' starting at 0, when 'i' is 2 it will be the last index of the array, and will check if 'i' + 1 < array. Current: public The array argument is treated as one value you want to wrap (you get a list of arrays of You can use java. Operator '==' compares object references, it checks to see if the two operands point to the same object (not equivalent objects, the same object). Ex: arr1={1,2,3,1,2,3} arr2={3,2,1} Method should return true (=both arrays are same). However, result2 is also an Array, Array's do not have a . This class offers constant time performance for the basic operations (add, remove, contains and size) ArrayList. Once that's complete, iterate the HashMap, any entry who has a value with size() > 1 has duplicates. Have in mind that array length is dynamic, also array values. It is the best thing to do if your array is not guaranteed to be sorted. println(rs. Array; /** * Checks an arbitrary number of parallel arrays to verify that they have the same length. How to check if a Map has duplicate key? 1. so the first time I check it will be true & I'll prep the list to do stuff. But not able to find how many times it occur or present in list Suppose I have an array which contains the values . stream(words). check whether all the values in array is same or not in javascript. I see if value in index 0 is equal or not equal to value in index 2. Which is not as you create a new item each time. How do I write the code without using any collections classes. Arrays class for useful methods. For every value, check and see if any of the values after that value are the same. I have an array that could contain objects. if they do - save the element. Because if the list contains 5 null values, then also its size will be 5. I need to check if two 2 dimensional arrays of [5][5] contain the same values even if one is shuffled. It only applies to different pair values though. Commented Jun 22, If you are using JAVA 5 or above ,you can use Arrays. – You could leverage Array. Array): import java. 3. yes, there is duplicate, assigning duplicate to true. For example testing an array that has 5 . So, if all the elements are in fact equal, the performance should be identical to Array#every. Since java lacks reified generics it may also be worth mentioning the cost Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company In Java when you use the "==" operator on an object you are checking if this is the same object instance. Viewed 3k times If you want to check if 2 arrays have the same elements in the same order, all you need to do is compare each element in turn. getString("COLUMN_NAME"); resultTemp[1] = rs. The list will be empty if You can call the constructor for these collections with the parameter Arrays. I was working on he same problem and came up with a small optimized solution to find the surrounding numbers of any point in a 2D matrix, hope this helps, please comment if I can shorten the logic somehow Code:- java - searching As you scan the array, if the value isn't in the HashMap, add it w/ a new collection of the index. net background. if input has foo: undefined and in array does no object has this key, the value is missing, because for not set properties, the value is undefined, which is in this case a state and in the given object for checking, it's a value. ex. Makes things lot simpler. Yes, creation would be slower, however lookups in a HashSet are O(1) whereas in an ArrayList they are O(n), hence my statement about how many times the OP wished to find out this information. How should I check if there is an element or nothing in a certain index of an array in java. public static boolean containsAllIntegers(String integers){ String[] newArray = integers. deepEquals method. Sets do not have duplicates. every(elem => [1,2]. After that system prints out "What number are you looking for?". The difference in performance between an ArrayList and a HashMap is that finding an element in a HashMap takes O(1) time, finding an element from an ArrayList can take up to O(n) time if you are not searching by index. util. How to set the same value for a range in an array in Java in one line? Ask Question Asked 6 years, 6 months ago. For example indices 0 through 10 will have "Bob," indices 11 - 57 will have "Jake I have an array list of usernames and an array list of passwords. It would be a Scanner method*/ matrix = new int[rows][columns This function runs in O(n log(n) + m log(m)) compared to O(n*m) (as seen in the other solutions with loops/indexOf) which can be useful if you are dealing with lots Unfortunately the solution with the allSame method using a HashSet was deleted nevertheless a little (non representative) performance test with 1_000_000 strings with 1. mabe a different use makes ir a bet more clear. [2021 changelog: bugfix for option4: no total ordering on js objects (even excluding NaN!=NaN and '5'==5 ('5'===5, '2'<3, etc. If it was {2,2,2,2,5}, it would return false because they are not different pair values. Please note that, I'm not asking for a list that cannot contain null. . Finding the same property value in an array of objects. equals () method to check if two arrays of integers are equal or not. const array = ["a", "b", , "d"]; array. Arrays if you don't want to implement it yourself:. name. check arraylist element equals an array. I've realised my code below only checks to see if the first index is the same as the second, not checking if the first index is the same as the third, fourth and so on. In this function I use if statement to compare two values but how can I use an array of values instead of variables if I want to use more than two values? For example: console. – stakahop. How can I check whether two arrays (cyclic) has the same elements in the same order. net. keys() (though you can on Object. In this case I want to check the value in array[18]. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog Now i want to know all keys whose value is x (ans: [1,3] ). – Joel Fernando. How to find a way to make my code count the number of matching elements in two arrays of the same size (same value, same position). The array is an int type and have initialized with a value i*j. A Hashmap stores key-value pairs and each key has to be unique. Test class: class Test { final Integer start; final Integer end; public Test(Integer s, Integer e) { this. ) 3rd value differs from all others: for-loop:0ms, set:31ms, stream:47ms, 2. nextInt("Insert the number of columns of the matrix"); }while(rows<=0 && columns<=0); /*Teclado = A java class that I use with methos like nextInt, nextByte, etc with their try catchs and so on. Simple iteration using for loop; List contains() method; Stream anyMatch() method; Arrays Arrays. Let's assign some values. I am trying to create a List of length 500, all indices initialized to 1000. For instance, if array1 has 5, 4, 3, 2, 1, and array2 has 1, 2, 3 checking whether two sequences have the same values in the same order (beginning java) Ask Question Asked 11 years ago. Does anyone know how I would work out if all elements in an array but one have the same value? I have been trying to work it out for ages but cannot solve it. Java 8. includes:. Also, $ is not a valid character in C's identifiers per the standard, although your compiler may happen to support it. I should note that in short int check[10] = {1,1,1,1,1,1,1,1,1}; only 9 elements are 1, the last element will be initialized to 0, so this check will always be false, if you omit the size i. sort(cmpFunc) on Map. C#: Compare two ArrayList of custom class and find duplicates. Commented Jan 18, 2020 at 17:33 Java 2D Array - Detect Duplicate Values. Arrays - which would both contain straightforward loops. The reason why Array#some is going to sometimes outperform is that once the callback function returns true, it stops iterating. For example : input : 2 1 2 2 1 Output : Yes (because that matrix doesnt has a same value in a row or a column. Java docs for HashSet says. It is used to check two arrays, whether single-dimensional or multi-dimensional, are equal or not. If you need to differentiate these two cases as well, starting from I have array named list which contains 12 elements. It always evaluates to the same Boolean value during the method call. names that somehow matches the one you are searching for - that's not how it works Creating List<Integer> with all same values in JAVA. Program to Check if Array has Same Values Java. if I want to do something in the list if the index is already there, but otherwise to prep it. It comes quite complicated if there are only or any null values in the array (resulting in a NullPointerException). If you assign a prime number to each possible string that can be in the array and then multiply all the elements of an array I may have to check three or more values as well. If any value is null "b" will be true. Generating an array of non-repeating integers. The way the Integer class is written in Java, any Integer is equal to another Integer if they represent the same value. Begin with an interval covering the whole array. what is best way to do? Brute force way is to just iterate over map and store all keys in array whose value is x. Next to which, this is the same if one instance is added to the list twice, which shouldnt happen, but could. return new HashSet<>(list). value => empty array insert turtle id into coord. indexOf(elem) > -1) I am simply trying to see if the inputted value matches a value that is already in the array and if it does return "Valid". asList(bob )); if (list. After that, the program will check if the matrix has the same value in a row or column. Something like this: /** * Will return a list of all indexes where the given value * exists in the given array. Checking whether you have two of the same elements in one integer array. 2. You can use a label, like this: I have a multidimensional array, I want to get the elements surrounding a particular element in that array. Follow import java. 1. I tried it like this, but then it checks for an array and not an element of an array: arrays in an arraylist, because I have a fixed number of columns (as suggested in how to create dynamic two dimensional array in java?). It'll also stop checking remaining values if the condition matches an element: let values = [1, 4, 6, -10, -83]; let hasNegative = values. My following code only works for 1 duplicate and unable to perform multiple duplicate detection. As ay89 rightly mentions, it is simpler to have an array with unique values (a set in other words), then check if your value is already contained before trying to add it. So if the first and last name of the employee is the same as the one already in the array, then return false. Note that this method treats slots valued undefined and empty slots the same, although they're not. In the following implementation, we hash the array. You have to create in every lopp a new Array: while (rs. check 1 == 2. I have a target array ["apple","banana","orange"], and I want to check if other arrays contain any one of the target array elements. Here's the code of what I have so far. length; int n = A[0]. 0. I've tried a I want to display the values in a HashMap. check 3 == 1. isEqual, it uses the static method equals from the Objects class and it will do the null check for you before calling equals How to Check if Array has Same Values Java | In this section, we will check whether the two arrays have the same elements or not. How do I do that? I would prefer not to use any special built-in is there any way to check if a collection contain a value or more with better performance than looping twice with contains? You could write your own loop that check both at once using a compiled regex Pattern that looks for either name at the same time: Pattern p = Pattern. equal(int[], int[]) implementation for some tips (check for equality + null checks). If all elements are same then print Yes To make the solution accept all object arrays, we can a generic method: if (array == null || array. I have tried this one, but this only check if the number IS If it is a tic-tac-toe game you should check for 3 of the same value in rows, columns and in the two diagonals. traversing the array and count what you want to count. Go through each value in the row. no, doing nothing. Just change the comparison operators to suit and ensure your date class is usable as a map key. Related. You can put all your elements into a Set and check if the size is 1, then all other elements were duplicates. lenght (3 < 3), will not go in, I believe the correct one would be to put '<=', because when reach 3 it will already be extrapolating the limit of the array The following snippets test for the "not contains" condition, as exemplified in the sample pseudocode in the question. Returning the largest value in an array. – Hovercraft Full Of Eels. At first I thought the What is the simplest way to find if two Lists contain exactly the same elements, in the standard Java libraries? It shouldn't matter if the two Lists are the same instance or not, and it shouldn't matter if the type parameter of the Lists are different. Already exists a method that takes a row number and value to search for. for example [10,2,5,1,8,20] returns 20 and 8 with the accepted solution. iyq cxoyyu zor abc wim kvz rcgdb fmgr vyqfehdb ifxlzx