The equals() method of java.util.AbstractList class is used to compare the specified object with this list for equality. Returns true if and only if the specified object is also a list, both lists have the same size, and all corresponding pairs of elements in the two lists are equal. (Two elements e1 and e2 are equal if (e1==null ? e2==null : e1.equals(e2)).) In other words, two lists are defined to be equal if they contain the same elements in the same order.
Syntax:
public boolean equals(Object o)
Parameters: This method takes the object o as a parameter to be compared for equality with this list.
Returns Value: This method returns true if the specified object is equal to this list.
Below are the examples to illustrate the equals() method.
Example 1:
// Java program to demonstrate// equals() method// for String value  import java.util.*;  public class GFG1 {    public static void main(String[] argv)        throws Exception    {          try {              // Creating object of AbstractList<String>            AbstractList<String>                arrlist1 = new ArrayList<String>();              // Populating arrlist1            arrlist1.add("A");            arrlist1.add("B");            arrlist1.add("C");            arrlist1.add("D");            arrlist1.add("E");              // print arrlist1            System.out.println("First ArrayListlist : "                               + arrlist1);              // Creating another object of AbstractList<String>            AbstractList<String>                arrlist2 = new ArrayList<String>();              // Populating arrlist2            arrlist2.add("A");            arrlist2.add("B");            arrlist2.add("C");            arrlist2.add("D");            arrlist2.add("E");              // print arrlist2            System.out.println("Second ArrayList : "                               + arrlist2);              // comparing first ArrayList to another            // using equals() method            boolean value = arrlist1.equals(arrlist2);              // print the value            System.out.println("Are both list equal : "                               + value);        }          catch (NullPointerException e) {            System.out.println("Exception thrown : " + e);        }    }} |
Output:
First ArrayListlist : [A, B, C, D, E] Second ArrayList : [A, B, C, D, E] Are both list equal : true
Example 2:
// Java program to demonstrate// equals() method// for Integer value  import java.util.*;  public class GFG1 {    public static void main(String[] argv)        throws Exception    {          try {              // Creating object of AbstractList<Integer>            AbstractList<Integer>                arrlist1 = new ArrayList<Integer>();              // Populating arrlist1            arrlist1.add(10);            arrlist1.add(20);            arrlist1.add(30);            arrlist1.add(40);            arrlist1.add(50);              // print arrlist1            System.out.println("First ArrayListlist : "                               + arrlist1);              // Creating another object of AbstractList<Integer>            AbstractList<Integer>                arrlist2 = new ArrayList<Integer>();              // Populating arrlist2            arrlist2.add(10);            arrlist2.add(20);            arrlist2.add(30);              // print arrlist2            System.out.println("Second ArrayList : "                               + arrlist2);              // comparing first ArrayList to another            // using equals() method            boolean value = arrlist1.equals(arrlist2);              // print the value            System.out.println("Are both list equal : "                               + value);        }          catch (NullPointerException e) {            System.out.println("Exception thrown : " + e);        }    }} |
Output:
First ArrayListlist : [10, 20, 30, 40, 50] Second ArrayList : [10, 20, 30] Are both list equal : false
