Count Duplicate String In Array Java

Question: (Duplicate Elimination) Use a one-dimensional array to solve the following problem: Write an application that inputs five numbers, each between 10 and 100, inclusive. Java Program to find duplicate Characters in a String By Chaitanya Singh | Filed Under: Java Examples This program would find out the duplicate characters in a String and would display the count of them. Well, so good so far, it's time to check the basic of java and basic of algorithm to find number of occurrence of all numbers from int array. There is exactly one number is repeated in the array. Scan the input string and construct a character count array from input string ie, In the above example, count of t is 2, so count['t'] = 2 count of u is 2, so count['u'] = 2 count of o is 1, so count['o'] = 1. How to find and remove duplicates in a Array / ArrayList 2. Finding Duplicate Elements in an Array - Java Program If you have to write a Java program to find duplicate elements in an array one option you have is to loop through the array taking one element at a time and then compare it with all the other elements of the array in order to find the duplicates. String[] split( String regularExpression ) - Splits the string according to given regular expression. I am going through the CodingBat exercises for Java. The program outputs a list of each unique value entered followed by the frequency of the number of times it occurred. Given a string, Write a program to remove duplcate characters from the string. Returns the number of duplicate values it works with arrays of any type, except objects The array is not REDIMed, but you can do it easily using the following code: a() is a string array. Download Run Code. We will discuss a couple of methods on how to insert an element in an array at a specified position. A protip by opinel about ruby, hash, array, enumerable, and count duplicate. We then create one HashMap with Character as a key and it’s number of occurrences as a value. For example, if an array with length 6 contains numbers {0, 3, 1, 2, 3}, then duplicated number is 3. The following Java program prints the smallest number in a given array. Only the constraints is to the solution should satisfy O(N) complexity. Taverna has a beanshell where I can program in java. Since there are n values from 1 to n-1 with one duplicate, we can use the fact that the sum of the integers from 1 to m is (m*(m+1))/2, take the sum from 1 to n-1, subtract that from the actual sum of numbers in the array, and the result will be the duplicated. Retain the first occurance of the duplicate character. As each number is read, display it only if it's not a duplicate of a number already read. But rather than cull them, one would like to find them with a routine that will return the indices of the duplicate items. Approach: Create a HashMap and character of String will be inserted as key and its count as value. String in Java is immutable. anyDuplicated() : an integer or real vector of length one with value the 1-based index of the first duplicate if any, otherwise 0. For example 7, 135, 214 are all unique numbers whereas 33, 3121, 300 are not. A basic fundamental on the usage of arrays is search an element in java array. To count total duplicate elements in given array we need two loops. You may use the sort method of arrays for sorting the numeric or string arrays. Write a program to find top two maximum numbers in a array. Java Program to Print Array Elements using For Loop. This example accesses the third element (2) in the second array (1) of myNumbers:. Instead of referring to the first revenue variable as Rev1, you can refer to it by using the array name and an index into the array, such as REVENUE[I] (assuming that I has a value of 1). Write a program Distinct. 5 KB) search for equal string in 2D array in java;. We can use a Java array as an array of immutable objects. Count the no. Java Examples: Collections - Count Duplicated Items In A List. Find step by step code solutions to sample programming questions with syntax and structure for lab practicals and assignments. 1- You can use a HashMap to find duplicate characters in a String along with repetition count. Java Examples: Strings - Count Unique Characters In A String. How to find duplicate words in a line of text 4. Java - limit number of duplicate characters in a string. Therefore a new String is created out of this array and its substring()method is called to remove the trailing duplicate characters using the updated length. In this example, we assign to an array position, overwriting the value at that position:. For this purpose, a for-loop can be used that loops from 0 to the total length of array -1 index. A basic fundamental on the usage of arrays is search an element in java array. Below is a program to find and remove any duplicate element present in the specified array. Java > AP-1 > commonTwo (CodingBat Solution) Problem: Start with two arrays of strings, a and b, each in alphabetical order, possibly with duplicates. Well, so good so far, it's time to check the basic of java and basic of algorithm to find number of occurrence of all numbers from int array. Java insertion sort with string array In this tutorial, you will learn how to sort array of strings using string array with Insertion Sort. 2D Array Determine Duplicate Home. anyDuplicated() : an integer or real vector of length one with value the 1-based index of the first duplicate if any, otherwise 0. Finding The Longest String In A String Array Initialize An ArrayList Iterate Through A HashMap Iterator Example. Find the element in the array possessing the highest value. We add all elements to LinkedHashSet, and then get back the content in array. split() is based on regex expression, a special attention is needed with some characters which have a special meaning in a regex expression. File Difference tool will help you to compare text files, XML, JSON, Code, String, binary files. Java program to count number of duplicate words in given string. Start with two arrays of strings, a and b, each in alphabetical order, possibly with duplicates. Here we show how to parse JSON data in Java using the org. Given an array of n-1 integers and these integers are in the range of 1 to n. How to find duplicate words in a line of text 4. Java program to count strings and integers from an array. Sort String in Java. contains? and get work on Java Maps, arrays, Strings, the latter two with integer keys. The most common way is using the split() method which is used to split a string into an array of sub-strings and returns the new array. During the first iterator it will count how many number of unique elemnts are available in an array. For example, in the array [1, 2, 2, 3, 3, 3], the two twos are one duplicate and so are the three threes. Java arrays start with an index of 0, so your increment number should always be initialized to 0. 1249-1265 (November 1993). If there are no characters left in the second string then both the strings are an anagram. A null input String returns null. We can make use of this property to check for duplicates in an array. The example also shows how to count duplicate elements in various ways. Formula to Count the Number of Occurrences of a Text String in a Range =SUM(LEN(range)-LEN(SUBSTITUTE(range,"text","")))/LEN("text") Where range is the cell range in question and "text" is replaced by the specific text string that you want to count. Java ArrayList. println is used to display the message "Duplicate Characters are as given below:". Contribute to qiyuangong/leetcode development by creating an account on GitHub. 1) No of item occurrence for a single item. Java Program to Check if An Array Contains a Given Value In this program, you'll learn to check if an array contains a given value in Java. Declare a Map to store the frequency of elements of inputArray. The output stream can be converted into List, Set etc using methods of Collectors such as toList(), toSet() etc. So if any character repeats, we should not be able to add that character to our HashSet and we know that string has duplicate characters!!!. I'm trying to create a program in Java which allows the user to pick from a list of coffees contained in a String array and continues on, but it fails the check and prints out the else statement. Array values can be accessed by position, with strong typing (the result is a primitive or SObject value of the Array member type). of duplicates in an array. 3 Ways to Find Duplicate Elements in an Array - Java There are multiple ways to find duplicate elements in an array in Java and we will see three of them in this program. 1) Created a string for no duplicates and another string for repeated character in a string 2) Iterated over the list of no duplicates and verified if each value in no duplicate is present in repeated character, else print the first value of no duplicate and break the loop. sort(arr) method. 'show the number of duplicates If Count > 1 Then Cells(i, col) = Count & " duplicates" End If 'reset count Count = 1 Next End Sub 'show only the biggest number of duplcates in a group Sub ShowMaxOnly(ByVal rng As String, ByVal col As Integer) Dim i, j As Integer Dim temp As Variant Range(rng). String contains a long tail of character with special character and normal character. You must use only constant, O (1) extra space. For this purpose, a for-loop can be used that loops from 0 to the total length of array -1 index. Use a HashSet in removeDuplicates. How many different ways do you know to. Repeat as long as the string has at least 3 bits. Online Java string programs and examples with solutions, explanation and output for computer science and information technology students pursuing BE, BTech, MCA, MTech, MCS, MSc, BCA, BSc. Because we want to go through each number in the array, this section basically says “loop from 0 to the last index in the array. This Java String to String Array example shows how to convert String object to String array in Java using split method. We will discuss a couple of methods on how to insert an element in an array at a specified position. You need to write a program to find that duplicate number. Java Tutorials,Scala Tutorials,Interview questions,Struts,Spring,HTML5,Design patterns,Java Puzzle,Java Quiz,jQuery Tutorials,jQuery Concepts,JavaScript,Java we will discuss how to remove duplicate characters from a String. Returns the number of duplicate values it works with arrays of any type, except objects The array is not REDIMed, but you can do it easily using the following code: a() is a string array. The following Java program prints the smallest number in a given array. For each of the methods with no parameters and a name starting with "get" or "is" followed by an uppercase letter, the method is invoked, and a key and the value returned from the getter method are put into the new JSONObject. Python filter() function is used to call a test function on a given iterable (list). The method for sorting arrays belongs to java. In this post of Java program to Remove Duplicate Elements From an Array We will look into three different methods to remove duplicate elements from an array. Programming Forum Debating on whether the parameters should simply be the 2D array by itself, or the array and the temporary number. Find duplicate elements in ArrayList; Creating Custom Generator class in Hibernate; CRUD Operations Using Hibernate; Creating our Own Hibernate Template class; Caused by: java. Input and Output Format: Input consists of a string with maximum size …. before storing a random number into the given array we have to consider 2 things. Sort String in Java. The type of the array and the array name. String getStringProperty(java. If you add the constraint that there be exactly one duplicate value, this is easy. Approach: Get the ArrayList with duplicate values. The program output is also shown in below. Use a HashSet in removeDuplicates. The separator is not included in the returned String array. How to count duplicate elements of ArrayList September 26, 2016 SJ Collection 0 In this article, we will count of number of duplicate elements present in List using Collections class’s utility frequency() method. It appears you're not just finding the duplicates, but also reporting which record number in the XML flie the duplicate account resides in. The user will enter the string and the program will find the count of each word and print out the result. There are two ways for this test - One is using equals() method provided in Arrays class and another by comparing each character of he words. For each of the element in the input array, check if it is present in the countMap, using containsKey() method. How can I use a quote " character within a string? Answer. If the array is empty the first form returns nil and the second form returns an empty array. Store it in some variable say size and arr. public java. I have an array of strings, some of which are duplicates. Java Program to Remove Duplicate Elements from Sorted Array - Duration: 5:43. This can be a Java program to find unique words in a string, also. 2 A few main points about arrays in Java: 3 Why using Arrays 4 Example of Java int array 5 An example of a string array 6 An example of …. Find Duplicate Elements in Array in C - Array is the collection of similar data type, In this program we find duplicate elements from an array, Suppose array have 3, 5, 6, 11, 5 and 7 elements, in this array 5 appear two times so this is our duplicate elements. Rotate an array of n elements to the right by k steps. This is one of the interview question which generally can asked in … Continue reading How to count occurrence of int in array in java →. The user will enter the string and the program will find the count of each word and print out the result. Now let us answer the below questions asked in various java interview questions which are given below 1. To count total duplicate elements in given array we need two loops. com, we won't encourage audio ads, popups or any other annoyances at any point, hope you support us :-) Thank you. In this method we will use hashing and remove all the duplicates in the input string 1. You can use Arrays, which has a method CharArray() that will create a char input string and using another method (Arrays. There are many methods through which you can find duplicates in array in java. Reverse an Array; Insert Element to Array; Delete Element from Array; Largest and Smallest Element in Array; Sum of N Numbers using Arrays; Sort Array Elements; Remove Duplicate Elements; Sparse Matrix; Square Matrix; Determinant of 2x2 matrix; Normal and Trace of Square Matrix; Addition and Subtraction of Matrices; Matrix Mulitplication. Finally, we use the Array. For each character, check if it is duplicate of already found characters. Sorting an array and removing duplicates can be done in many ways but I will discuss two ways. We then create one HashMap with Character as a key and it's number of occurrences as a value. There are so many similar questions you may get in an Interview like Create your own contains() method in java, find duplicate char from String, etc. First solution is the brute force algorithm which is demonstrate by finding duplicate element on integer array, but you can use the logic to find duplicate on any kind of array. Finding Duplicate Elements in an Array - Java Program If you have to write a Java program to find duplicate elements in an array one option you have is to loop through the array taking one element at a time and then compare it with all the other elements of the array in order to find the duplicates. If an element is found to be a duplicate, that element should then be exempt from the search so if that element is found again it should not increase the duplicate count. Write a program Distinct. A JSON object is an unordered set of key/value pairs. How many different ways do you know to. Java Forums on Bytes. File Difference tool will help you to compare text files, XML, JSON, Code, String, binary files. Filter out duplicate values in an array and compact the array by moving items to 'fill the gaps'. A field is like a C++ data member, and a method is like a C++ member function. Previous Next In this post, we will see how to find duplicate Characters in a String. 1249-1265 (November 1993). Douglas McIlroy's "Engineering a Sort Function", Software-Practice and Experience, Vol. Also the assumption that all duplicate characters are clubbed together (because of initial sorting) doesn’t hold while permuting. The values themselves could be objects or arrays. Find duplicate elements in ArrayList Unknown Sunday, January 25, 2015 Java , Programs No comments There are four ways is there to find duplicate element in arraylist. Easy #10 Regular Expression Matching. RhinoScript has a method to cull the duplicate strings. In above example, we get a Java program to count how many times a word appears in a String or find duplicate words. Tip: This algorithm limits the search for duplicate chars to the number of unique chars, not the total number of chars in the string. Imagine you have an array of strings which contains duplicates. You have a museum with a grid layout for its rooms. Duplicate is defined as two or more identical elements. To concatenate Lists, Sets and Arrays we will convert them into stream first and using concat() we will combine them. 1st approach : Change the array to a List of numbers. There are multiple ways to find duplicate elements in an array in Java and we will see three of them in this program. Input size and elements in array from user. The given Array does not contain duplicates or occurrence of each integer value is only once. Adjacent separators are treated as one separator. Arrays in general is a very useful and important data structure that can help solve many types of problems. It can help you in to find the most frequent words in a string also check the count which will be equal to one for unique words. I've tried many different things but can't seem to come up with code that gives me the correct answer (the number of duplicates in the array) no matter how many duplicates there are. That’s all for the topic Java Program to Find Longest Palindrome in The Given String. You can have an array of integers or an array of strings or an array of arrays, but you can't have an array that contains, for example, both strings and integers. Using String. Increment the count of each character by using ASCII of character as key ie, arr[s[i]]++ here, s[i] gives the ASCII of the present character 3. All items in a Java array need to be of the same type, for instance, an array can't hold an integer and a string at the same time. Sometime programmer may be asked to print count and starting position of the duplicate letter as well. Java Examples: Collections - Count Duplicated Items In A List. Java ‘int’ array examples (declaring, initializing, populating) | alvinalexander. It can help you in to find the most frequent words in a string also check the count which will be equal to one for unique words. Given an array of intergers, and need to count the number of duplicate array elements. put("stack", "overflow", "stack", "yahoo", "google", "msn", "MSN", "stack", "overflow", "user"); Map. Then , we will traverse char array and increment its value by 1 for each. int main() {. Declare a Map to store the frequency of elements of inputArray. You can count the number of duplicate elements in a list by adding all the elements of the list and storing it in a hashset, once that is done, all you need to know is get the difference in the size of the hashset and the list. In this program we are finding the occurrence of each character in a String. Given an array of integers, 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once. Array values can be accessed by position, with strong typing (the result is a primitive or SObject value of the Array member type). On one of our articles on how to convert an array to set, we have discussed a unique property of Set class of java Collections framework that doesn’t allow duplicates on its elements. Method 1 Using Extra Space. Write a java program to find missing number in array. If a string is long, the number of duplicate chars that must be searched is reduced. We have to write an efficient java code to find missing number from an array. I was wondering, what was the best way to clear out an array in peoplecode during saveprechange processing so that elements can be re-evaluated each time. Find Largest and Smallest Number in an Array Example. This tutorial demonstrates how to convert a list to an array in Java, using different array methods, the Apache Commons Lang, Commons Collection, and Guava. 3 Ways to Find Duplicate Elements in an Array - Java There are multiple ways to find duplicate elements in an array in Java and we will see three of them in this program. Now let us answer the below questions asked in various java interview questions which are given below 1. There are many ways to split a string in Java. Remove duplicates from an array java This is the java programming blog on "OOPS Concepts" , servlets jsp freshers and 1, 2,3 years expirieance java interview questions on java with explanation for interview examination. The idea is to insert all elements of the array into a HashSet. Count the number of duplicates words in the array. If There Are No Duplicates Then Your Program Should Output Should Print Out According To The Expected Output Below. If sort_flags is SORT_STRING, formerly array has been copied and non-unique elements have been removed (without packing the array afterwards), but now a new array is built by adding the unique elements. Java ArrayList. For each of the element in the input array, check if it is present in the countMap, using containsKey() method. This is a hex dump of a class file, excluding the header and constant pool. Unlike PHP where we can use numeric keys and strings for indexes in an ad hoc way and still get an accurate count via count(), in JS it’s not quite the same. Here is my code:. After the introduction of Collection framework performing this operation is a pretty easy task. Next, it is going to count the total number of duplicate elements present in this array using For Loop. In this tutorial, I'll show how to declare, populate, and iterate through Java string arrays, including the newer for-loop syntax that was introduced with Java 5. I have used HashSet to find duplicates. If they are the same it adds a duplicate to the return array. In above example, we get a Java program to count how many times a word appears in a String or find duplicate words. arraycopy - useful when copying parts of an array; call its clone method, and do a cast - the simplest style, but only a shallow clone is performed. For example, you can create an array that can hold 100 values of int type. Program to find occurrence of a character in a string. Following is the java program to find duplicate or repeated characters from a given string. seq works on Java reference arrays, Iterables and Strings. println is used to display the message "Duplicate Characters are as given below:". Wrie a program to find out duplicate characters in a string. Write a program that reads in a binary string from the command line and applies the following (00, 1101) tag-system: if the first bit is 0, delete the first three bits and append 00; if the first bit is 1, delete the first three bits and append 1101. An additional integer array will be used to store the number of duplicates of each word. The ArrayList class is a resizable array, which can be found in the java. There are 2 ways to replace methods in a Java String. Contribute to qiyuangong/leetcode development by creating an account on GitHub. The number of resultant sub-strings by splitting the string is controlled by limit argument. (The union of two sets is the set containing all of the elements contained in either set. Question: (Duplicate Elimination) Use a one-dimensional array to solve the following problem: Write an application that inputs five numbers, each between 10 and 100, inclusive. In this program we are finding the occurrence of each character in a String. remove duplicates from array. Array is the collection of similar data type, In this program we find duplicate elements from an array, Suppose array have 3, 5, 6, 11, 5 and 7 elements, in this array 5 appear two times so this is our duplicate elements. Write a Program in Java to input a number and check whether it is a Unique Number or not. Algorithm to count duplicate elements in an array Let inputArray is an integer array having N elements. For example, in the array [1, 2, 2, 3, 3, 3], the two twos are one duplicate and so are the three threes. In this post we'll see both solutions. That's all about how to find duplicate elements in an array. toArray(String[]::new); For the non-primitive types, it will also do a shallow copy of objects. Online Java string programs and examples with solutions, explanation and output for computer science and information technology students pursuing BE, BTech, MCA, MTech, MCS, MSc, BCA, BSc. Example 1: Check if Int Array contains a given value. A JSON array is an ordered collection of values. Next, we are using For Loop to iterate each element in this array, and print those array elements. If array is not sorted, you can sort it by calling Arrays. There are many ways to split a string in Java. Next, it is going to count the total number of duplicate elements present in this array using For Loop. Counts all elements in an array, or something in an object. Result: The loop that accesses the array length directly is faster. Java Program to Count Number of Words in Given String; Java Program to Count the Number of Occurrences of Substring in a String; Java Program to Count the Occurrences of Each Character in String; Java Program to Merge two String Arrays ; Java Program to Remove Duplicate Words from String ; Java Program to Reverse a String(5 ways) Java Program. Logic Used To Find Duplicate Characters In A String In Java : We use HashMap and Set to find the duplicate characters in a string. String getStringProperty(java. println() (1) Java Example Programs interview (1) Java Interview programs on Strings (1) Java Object Oriented (1). Part 2: Fill-in Find Duplicate Count. For example, with n = 7 and k = 3, the array is rotated to. Nov 7 2008 1:36 AM. Dec 25, 2015 Array, Core Java, Examples comments. Select i = 1 For i = 1 To Selection. Finding Duplicate Elements in an Array - Java Program If you have to write a Java program to find duplicate elements in an array one option you have is to loop through the array taking one element at a time and then compare it with all the other elements of the array in order to find the duplicates. It returns the length of the array with unique elements, but the original array need to be changed also. util package. In the sequence 4 8 6 1 2 9 4 the minimum distance is 1 (between 1 and 2). For every element inputArray[i], where (0 =i=N-1). The separator is not included in the returned String array. How to find and print duplicate words or lines in a File 3. Java – Remove Duplicate Number from Array (1) Java – Reverse String without using Reverse function (1) Java Difference Between (1) Java example program to print message without using System. A good thing about the string is that if you know the array, you can solve string-based questions easily, because strings are nothing but a character array. Need help? Post your question and get tips & solutions from a community of 445,005 IT Pros & Developers. Java int array find duplicate elements example shows how to find duplicate elements in an int array. That’s all for the topic Java Program to Find Longest Palindrome in The Given String. In this tutorial, you will see to letter count we are not going to use any of special methods or functions while count number of characters in a string java. identifier must be either an string or a number because we have to store it as a key inside the identifierState. I need to be able to list the items that have duplicates and the number of times the items shows up. Your program or method should take an array of integers as input and should return another array which should contain only unique elements from the input array. What i mean is say for example "Employee" class has a property "empName" and i do. The comparison is case-sensitive, so if you need it to be case-insensitive, you can make sure that both of your comparison Strings to either upper case or lower case before calling countMatches() with these Strings. This tutorial demonstrates how to convert a list to an array in Java, using different array methods, the Apache Commons Lang, Commons Collection, and Guava. search example. Construct a JSONObject from an Object using bean getters. There are different way to get this done but this is simple and straight forward. Initialize another variable count with 0 to store duplicate count. For example if the array contains {1,2,3,2,1,4} then {1,2} duplicate elements and output should be 2. This can be a Java program to find unique words in a string, also. How to Sort an Array in Java. Find duplicate elements in ArrayList - This example will show, how to find no of duplicate item occurrence from a ArrayList. A Java example to show you how to count the total number of duplicated entries in a List, using Collections. You could use the String. Need help? Post your question and get tips & solutions from a community of 445,005 IT Pros & Developers. Write a program for Insertion Sort in java. To concatenate Lists, Sets and Arrays we will convert them into stream first and using concat() we will combine them. For objects, if you have SPL installed, you can hook into count() by implementing interface Countable. Group Console. println is used to display the message "Duplicate Characters are as given below:". If Hashamap already contains char,increase its count by 1, else put char in HashMap If value of Char is more than 1, that means it is duplicate character in that String Java Program to find duplicate Characters. Those numbers get stored in an array and accordingly at the end of program, it displays the frequency of a number that was entered. Set to Array Conversion source code. (The union of two sets is the set containing all of the elements contained in either set. Note that to perform the count, first the Split method is called to create an array of words. frequency and Map. First, we convert the given string to char array. Submitted by Preeti Jain , on March 13, 2018 Given an array of integers and we have to remove duplicate elements using java program. I have used HashSet to find duplicates. I got everything except for the part that count the frequencies of the integers. To access the elements of the myNumbers array, specify two indexes: one for the array, and one for the element inside that array. Since there are n values from 1 to n-1 with one duplicate, we can use the fact that the sum of the integers from 1 to m is (m*(m+1))/2, take the sum from 1 to n-1, subtract that from the actual sum of numbers in the array, and the result will be the duplicated. String Arrays. JSON stands for JavaScript Object Notation, and it is based on a subset of JavaScript. split() is based on regex expression, a special attention is needed with some characters which have a special meaning in a regex expression. Java Examples: Strings - Count Unique Characters In A String. Returns (Array): Returns the new duplicate free array. Java Program to Generate Random Numbers. There are two ways to declare string array - declaration without size and declare with size. You may use the sort method of arrays for sorting the numeric or string arrays. one way of doing this, is to use another type of array (e. The inner loop will be used to compare the selected element with the rest of the elements of the array. Version 1: This code loops over a 100,000 element array and accesses array. The best "linear" solution makes a single pass over both arrays, taking advantage of the fact that they are in alphabetical order. Let's see them one by one. Split method is newer method in java, StringTokenizer was old method and previous …. In this post, we will discuss three ways to count the number of occurrences of a char in a String in Java. Quickly finding duplicates in an ArrayList. This Java program is the same as the above. Java Advance For loop : Print an array of Integers. However, when I run my program, my return arraylist is returning an empty arraylist. Merge two arrays; Remove. In this tutorial, you will see to letter count we are not going to use any of special methods or functions while count number of characters in a string java. By candid | Posted : 16 May,. To remove the duplicate element from array, the array must be in sorted order. Then , we will traverse char array and increment its value by 1 for each. Here we show how to parse JSON data in Java using the org. Return the count of the number of strings which appear in both arrays. I was wondering, what was the best way to clear out an array in peoplecode during saveprechange processing so that elements can be re-evaluated each time. The ArrayList class is a resizable array, which can be found in the java. In this code snippet we will learn how we can count number of duplicate values in an array in C# programming. Approach: Get the ArrayList with duplicate values. Remove duplicate characters in a given string keeping only the first occurrences.