Boolean Data Type in Java: Definition and Usage Explained

boolean Data Type in Java

Boolean category data type is used for representing or storing logical values is true or false. In java programming to represent Boolean values or logical values, we use a data type called Boolean.Values of type boolean are not converted implicitly or explicitly (with casts) to any other type. But the programmer can easily write conversion code.

• boolean is primitive data type in Java.
• boolean data type represents one bit of information
• Boolean data type is used for logical values.
• There are only two possible values: true and false
• This data type is used for simple flags that track true/false conditions
• Default value is false
• "Boolean" is wrapper class for "boolean" primitive data type.
• Example:

  boolean one = true;

Variable Declaration and Variable Initialization:

Variable Declaration : To declare a variable , you must specify the data type & give the variable a unique name.

boolean flag;

Variable Initialization : To initialize a variable you must assign it a valid value.

flag = true;

Variable Declaration and Variable Initialization in two Step :

boolean flag;
flag = true;

---

Example :

Save Source File Name as : HelloWorld.java
To compile : javac HelloWorld.java
To Run : java HelloWorld

// A Java program to demonstrate boolean data type
class HelloWorld { 
   public static void main(String args[])
     { 
           boolean flag; 
           flag = true;
           System.out.println(flag); 
     } 
   }

Output

true

Variable Declaration and Variable Initialization in one Step :

boolean flag = true;

---

Example :

// A Java program to demonstrate boolean data type
class HelloWorld { 
   public static void main(String args[])
     { 
           boolean flag = true;
           System.out.println(flag); 
     } 
   }

Output

true

A Java program to demonstrate boolean data type

Example 1:

Save Source File Name as : BooleanExample1.java
To compile : javac BooleanExample1.java
To Run : java BooleanExample1

// A Java program to demonstrate boolean data type
class BooleanExample1
{
    public static void main(String args[]) 
    {
        boolean b = true;       
        if (b == true)
        System.out.println("Hi Geek");
    }    
}

Output:

Hi Geek

Example 2:

Save Source File Name as : BooleanExample2.java
To compile : javac BooleanExample2.java
To Run : java BooleanExample2

// A Java program to demonstrate boolean data type
class BooleanExample2
{
public static void main(String args[]) {

 boolean a,b,c;

 a  = true;  // Assigning Value
 b  = false; // Assigning Value
 c  = b;    // Assigning Variable

 System.out.println(a); // Printing Value
 System.out.println(b); // Printing Value
 System.out.println(c); // Printing Value

 }
}

Output:

true
false
false

Different Ways of Using Boolean Value :

Way 1 : Inside If Statement

class BooleanExample3
{
public static void main(String args[])
{
 boolean b;

 b = true;

 if(b)
   {
   System.out.println("I am True");
   }
 }
}

Boolean Value is used to check whether condition is true or not.

No need to do == to check equality

class BooleanExample4
{
public static void main(String args[])
{
 boolean b;

 b = true;

 if(b == true)
   {
   System.out.println("I am True");
   }
 }
}

Way 2 : Comparing Two Numbers

class BooleanExample5 {

public static void main(String args[]) {

 boolean b;

 b = (10 > 6);

 if(b)
   {
   System.out.println("10 > 6");
   }
 }
}

we can use boolean value to hold the result Comparison operators. here 10 > 6 therefor true will be stored in boolean variable