Java boolean keyword is used to declare a variable as a boolean
type which represents only one of two possible values i.e. either true
or false
.
In java, by default boolean
variables are initialized with false.
boolean keyword can be used with –
- Variables
- Method parameters
- Method return types
Please note that size of boolean in Java is not precisely defined and it depends upon the Java Virtual Machine (JVM).
1. Java boolean syntax
The boolean keyword can be used as shown in given examples.
//1. variable boolean isMajorVersion = false; //2. method parameters public void setValid( boolean valid ) { //code } //3. method return type public boolean isValid() { //code }
2. Java Boolean class
We have a class java.lang.Boolean
(with ‘B’ in capital) in Java. Boolean class is a wrapper class provided to wrap boolean primitive value. It has a single field of type boolean.
We can assign a boolean primitive values to Boolean object directly. It is called autoboxing in Java where primitive values are automatically converted to their wrapper classes.
Boolean b = new Boolean( true ); //or Boolean b = true; //autoboxing
3. Java boolean example
Java program to show the usage of boolean keyword.
public class Main { public static void main(String[] args) { boolean condition = true; if(condition) { System.out.println("Condition is true"); } else { System.out.println("Condition is false"); } Boolean condObj = condition; System.out.println(condObj.booleanValue()); } }
Program output.
Condition is true true
Happy Learning !!