Reading a Method Signature From Left to Right

One line from a real class, with five separate decisions packed into it. Read left to right and each word answers one question.

java

public static int add(int a, int b) {
    return a + b;
}

Each part of the signature, and the question it answers
Part	Question it answers
`public`	Who may call it
`static`	Does it belong to the class rather than to one object
`int`	What does it hand back
`add`	What do callers write
`(int a, int b)`	What must callers supply, and in what order

Two of those are worth reading carefully. The return type is the promise: declaring int means every path through the body has to end in a return of an int, and the compiler checks every path. Declaring void means the opposite promise — the method produces nothing, and return someValue; inside it will not compile.

What to notice: the parameter list is the only part that decides which method a call matches, and the return type is not part of that decision at all.