Questions tagged [void]

Programming languages derived from C or Algol68, like C++, C#, Java, etc., may define the return type of methods/functions as void when the method/function does not return a value, but simply completes execution.

An example of its use in Java, compared to a non-void method, is:

int nonVoidMethod {
    // do something
    return 0; // return a value to the caller
}

void voidMethod {
    // do something
    return; // no value allowed to be returned from a void method
    // a "return" statement is not required
}

Although void is used as a type, it's an incomplete type:

• In some languages, such as Java and Algol68, void is only a keyword used as a return type. It is not considered as a valid type in other language constructs.

• Other languages, like C and C++, consistently define void as a type with an empty set of values. This allows its use for example in compound type constructs (void pointers). But no void objects can be instantiated.