Java gives a strategy to contrasting two Array List. The ArrayList.equals() is the strategy utilized for contrasting two Array List. It analyzes the Array records as, both Array records ought to have a similar size, and all relating sets of components in the two Array records are equivalent.
Example:
Input : ArrayList1 = [1, 2, 3, 4], ArrayList2 = [1, 2, 3, 4] Output: Array List are equal Input : ArrayList1 = [1, 2, 3, 4], ArrayList2 = [4, 2, 3, 1] Output: Array List are not equal
Syntax:
boolean equals(Object o)
Parameters:
Implementation:
// Comparing two ArrayList In Java import java.util.ArrayList; public class GFG { public static void main(String[] args) { // create two Array List ArrayList ArrayList1 = new ArrayList(); ArrayList ArrayList2 = new ArrayList(); // insert items in AyyarList 1 ArrayList1.add("item 1"); ArrayList1.add("item 2"); ArrayList1.add("item 3"); ArrayList1.add("item 4"); // insert items in AyyarList 2 ArrayList2.add("item 1"); ArrayList2.add("item 2"); ArrayList2.add("item 3"); ArrayList2.add("item 4"); // Display both ArrayList System.out.println(" ArrayList1 = " + ArrayList2); System.out.println(" ArrayList1 = " + ArrayList1); // compare ArrayList1 with ArrayList2 if (ArrayList1.equals(ArrayList2) == true) { System.out.println(" Array List are equal"); } else // else block execute when // ArrayList are not equal { System.out.println(" Array List are not equal"); } // insert one more item in ArrayList 1 System.out.println( "\n Lets insert one more item in Array List 1"); ArrayList1.add("item 5"); // display both ArrayList System.out.println(" ArrayList1 = " + ArrayList1); System.out.println(" ArrayList = " + ArrayList2); // again compare ArrayList 1 with ArrayList 2 if (ArrayList1.equals(ArrayList2) == true) { System.out.println(" Array List are equal"); } else { System.out.println(" Array List are not equal"); } } }
Output:
ArrayList1 = [item 1, item 2, item 3, item 4] ArrayList1 = [item 1, item 2, item 3, item 4] Array List are equal Lets insert one more item in Array List 1 ArrayList1 = [item 1, item 2, item 3, item 4, item 5] ArrayList = [item 1, item 2, item 3, item 4] Array List are not equal
Time Complexity: O(N), where N is the length of the Array list.