How to Compare two Collections in Java?
Java Collection provides an architecture to store and manipulate the group of objects. Here we will see how to compare Elements in a Collection in Java.
Steps:
- Take both inputs with help of asList() function.
- Sort them using Collections.sort() method.
- Compare them using equals() function.
- Print output. (true means both are equal and false means both are different)
Example 1:
Java
// Java program implementing// Comparing elements of Collections import java.util.*;import java.io.*; public class ArrayCompareExample { // main function accepting string arguments public static void main(String[] args) { // create listA ArrayList<String> listA = new ArrayList<>(Arrays.asList("a", "b", "c")); // create listB ArrayList<String> listB = new ArrayList<>(Arrays.asList("a", "b", "d")); // sorting both lists Collections.sort(listA); Collections.sort(listB); // Compare lists using // equals() method boolean isEqual = listA.equals(listB); // print output on screen (true or false) System.out.println(isEqual); }} |
Output
false
Example 2:
Java
// Java program implementing// Comparing elements of Collections import java.util.*;import java.io.*; public class ArrayCompareExample { // main function accepting string arguments public static void main(String[] args) { // create listA ArrayList<Integer> listA = new ArrayList<>(Arrays.asList(3, 4, 5)); // create listB ArrayList<Integer> listB = new ArrayList<>(Arrays.asList(4, 5, 3)); // sorting both lists Collections.sort(listA); Collections.sort(listB); // Compare lists using // equals() method boolean isEqual = listA.equals(listB); // print output on screen (true or false) System.out.println(isEqual); }} |
Output
true
