The equals() method of java.util.TreeSet class is used to compare the specified object with this set for equality. Returns true if and only if the specified object is also a set, both sets have the same size, and all corresponding pairs of elements in the two sets are equal. (Two elements e1 and e2 are equal if (e1==null ? e2==null : e1.equals(e2)).) In other words, two sets 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 set.
Returns Value: This method returns true if the specified object is equal to this set.
Below are the examples to illustrate the equals() method.
Example 1:
// Java program to demonstrate equals() // method of TreeSet import java.util.*;
public class GFG {
public static void main(String[] argv)
{
// Creating object of TreeSet<String>
TreeSet<String>
set1 = new TreeSet<String>();
// Populating set1
set1.add( "A" );
set1.add( "B" );
set1.add( "C" );
set1.add( "D" );
set1.add( "E" );
// print set1
System.out.println( "First TreeSet: "
+ set1);
// Creating another object of TreeSet<String>
TreeSet<String>
set2 = new TreeSet<String>();
// Populating set2
set2.add( "A" );
set2.add( "B" );
set2.add( "C" );
set2.add( "D" );
set2.add( "E" );
// print set2
System.out.println( "Second TreeSet: "
+ set2);
// comparing first TreeSet to another
// using equals() method
boolean value
= set1.equals(set2);
// print the value
System.out.println( "Are both set equal: "
+ value);
}
} |
First TreeSet: [A, B, C, D, E] Second TreeSet: [A, B, C, D, E] Are both set equal: true
Example 2:
// Java program to demonstrate equals() // method of TreeSet import java.util.*;
public class GFG1 {
public static void main(String[] argv)
{
// Creating object of TreeSet
TreeSet<Integer>
set1 = new TreeSet<Integer>();
// Populating set1
set1.add( 10 );
set1.add( 20 );
set1.add( 30 );
set1.add( 40 );
set1.add( 50 );
// print set1
System.out.println( "First TreeSet: "
+ set1);
// Creating another object of TreeSet
TreeSet<Integer>
set2 = new TreeSet<Integer>();
// Populating set2
set2.add( 10 );
set2.add( 20 );
set2.add( 30 );
// print set2
System.out.println( "Second TreeSet: "
+ set2);
// comparing first TreeSet to another
// using equals() method
boolean value = set1.equals(set2);
// print the value
System.out.println( "Are both set equal: "
+ value);
}
} |
First TreeSet: [10, 20, 30, 40, 50] Second TreeSet: [10, 20, 30] Are both set equal: false