Java boolean Keyword

The boolean keyword in Java is used to declare a boolean variable or to specify the return type of a method.

A boolean variable can hold a true or false value, and it is a primitive data type that occupies one byte of memory. To declare a boolean variable, you can use the following syntax:

boolean flag = true;

Here, flag is a boolean variable that is initialized to true.

You can also use the boolean keyword as the return type of a method to indicate that the method returns a boolean value. For example:

public boolean isEven(int x) {
    return x % 2 == 0;
}

In this example, the isEven() method takes an integer as input and returns a boolean value indicating whether the number is even or not.

You can also use the boolean keyword as a parameter type for a method or a constructor. For example:

public void setFlag(boolean flag) {
    this.flag = flag;
}

In this example, the setFlag() method takes a boolean value as a parameter and sets it to a class variable.

Boolean values can be used in control statements such as if, while, and for to control the flow of execution of a program. They can also be used in expressions and conditions. For example:

int x = 10;
int y = 20;
boolean result = x > y; // result is false

In this example, the boolean expression x > y evaluates to false and is assigned to the result variable.