The boolean data type has only two valid values: true and false.
These two values are called boolean literals.
We can use boolean literals as
boolean done; // Declares a boolean variable named done done = true; // Assigns true to done
A boolean variable cannot be cast to any other data type and vice versa.
boolean
is the type returned by all relational operators, as in the case of a < b.
boolean
is the type required by the conditional expressions
that govern the control statements such as if
and for
.
Here is a program that demonstrates the boolean type:
public class Main { public static void main(String args[]) { boolean b;/* w w w . java 2s .co m*/ b = false; System.out.println("b is " + b); b = true; System.out.println("b is " + b); b = false; if (b) System.out.println("This is not executed."); // outcome of a relational operator is a boolean value System.out.println("10 > 9 is " + (10 > 9)); } }
The code above generates the following result.