How to pass parameters and return values

Declare parameters

Parameters are typed variables listed in the method declaration. Arguments supply their values at a call site.

static void greet(String name) {
    System.out.println("Hello, " + name);
}

greet("Ada");

Return a value

The return type states what the method produces. return ends the method and sends a compatible value back.

static int square(int number) {
    return number * number;
}

int result = square(5);

Pass several arguments

Arguments must match parameter order and compatible types.

static double total(double price, int quantity) {
    return price * quantity;
}

System.out.println(total(9.5, 3));

Understand value passing

Java passes every argument by value. For an object, the copied value is a reference, so a method can mutate that object but cannot replace the caller's variable.