Java boolean Keyword

In Java, the boolean keyword is a primitive data type. It is used to store only two possible values, either true or false. It specifies 1-bit of information and its "size" can't be defined precisely.

The boolean keyword is used with variables and methods. Its default value is false. It is generally associated with conditional statements.

Examples of Java boolean keyword

Example 1: Simple boolean example

public class BooleanExample1 {

	public static void main(String[] args) {
	
		int num1=10;
		int num2=20;
		
	boolean b1=true;
	boolean b2=false;

if(num1<num2)
{
	System.out.println(b1);
}
else
{
	System.out.println(b2);
}
		
	}		
}

Test it Now

Output:

true

Example 2: Comparing the variables of boolean type

public class BooleanExample2 {

	public static void main(String[] args) {
	
	boolean b1=true;
	boolean b2=false;
	boolean b3=(b1==b2);
	
	System.out.println(b1);
	System.out.println(b2);
	System.out.println(b3);
		
	}		
}

Test it Now

Output:

true
false
false

Example 3: Method of boolean type

public class BooleanExample3 {

	public static boolean display(int num)
	{
		if(num>10)
		{
			return true;
		}
		else
		{
		return false;
	}
		}
	
	
	public static void main(String[] args) {
	
		
		System.out.println(display(15));
		
	}		
}

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Output:

true

Example 4: Comparing objects

public class BooleanExample4 {

	public static void main(String[] args) {

		BooleanExample4 b1=new BooleanExample4();
		BooleanExample4 b2=new BooleanExample4();
		
		boolean result=(b1==b2);
		System.out.println("Is objects are equal : "+result);
				
	}		
}

Test it Now

Output:

Is objects are equal : false

Example 5: Finding a prime number

public class BooleanExample5 {

  
  
	public static void main(String[] args) {

		int num=7;
		boolean flag=false;

		  for(int i=2;i<num;i++)
		  {
			  if(num%i==0)
			  {
				  flag=true;
                          break;
			  }
		  }
		if(flag)
		{
			System.out.println("Not prime");
		}
		else
		{
			System.out.println("prime");
		}
		
	}		
}

Test it Now

Output: