Programming Tutorials

Use of return statement in Java

By: Emiley J  

The last control statement is return. The return statement is used to explicitly return from a method. That is, it causes program control to transfer back to the caller of the method. As such, it is categorized as a jump statement. A brief look at return is presented here.

At any time in a method the return statement can be used to cause execution to branch back to the caller of the method. Thus, the return statement immediately terminates the method in which it is executed. The following example illustrates this point. Here, return causes execution to return to the Java run-time system, since it is the run-time system that calls main( ).

// Demonstrate return.
class Return {
public static void main(String args[]) {
boolean t = true;
System.out.println("Before the return.");
if(t) return; // return to caller
System.out.println("This won't execute.");
}
}

The output from this program is shown here:

Before the return.

As you can see, the final println( ) statement is not executed. As soon as return is executed, control passes back to the caller.

One last point: In the preceding program, the if(t) statement is necessary. Without it, the Java compiler would flag an "unreachable code" error, because the compiler would know that the last println( ) statement would never be executed. To prevent this error, the if statement is used here to trick the compiler for the sake of this demonstration.

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