Call by Value

The type of parameter passing that Java uses is called call by value. Some programming languages use other methods of parameter passing, and some give the programmer a choice among several ways to pass parameters. The call by value method that Java uses is the most common method in modern languages and is the easiest and safest.

This is how call by value works:

1. When the caller invokes a method, the caller provides a list of values (the actual parameters) in the parameter list.
2. When the invoked method starts running, these values are copied to the formal parameters.
3. The invoked method uses the formal parameters to access these copied values.
4. Any change the method makes to the value held in a formal parameter changes only that copy.
5. The invoked method cannot use the formal parameters to send a value back to the caller.