When a method has no parameters, what is necessary in both the method heading and call?

In Java, when a method is defined without parameters, it is necessary to include empty parentheses in both the method heading and the method call. This is because the parentheses are part of the method syntax and indicate that the method does not take any input arguments.

For example, if you have a method defined like this:

public void myMethod() {

// method implementation

}

You would also call this method by using empty parentheses, like this:

myMethod();

This syntax clearly differentiates the method from other types of code structures and makes it evident that there are no parameters to be passed to the method upon invocation. Without the parentheses, it would not be recognized as a method call in Java.

While other choices touch on various aspects of Java methods, they do not specifically address the necessity of empty parentheses for methods with no parameters, making the inclusion of empty parentheses the correct requirement for both method headers and calls.