JavaScript Functions

JavaScript Function Syntax

A JavaScript function is defined with the function keyword, followed by a name, followed by parentheses ().
Function names can contain letters, digits, underscores, and dollar signs (same rules as variables).
The parentheses may include parameter names separated by commas:
(parameter1, parameter2, ...)
The code to be executed, by the function, is placed inside curly brackets: {}
function name(parameter1, parameter2, parameter3) {
    code to be executed
}

Function Return

When JavaScript reaches a return statement, the function will stop executing.
If the function was invoked from a statement, JavaScript will "return" to execute the code after the invoking statement.
Functions often compute a return value. The return value is "returned" back to the "caller":

Example

Calculate the product of two numbers, and return the result:

var x = myFunction(4, 3);    // Function is called, return value will end up in x
function myFunction(a, b) {
    return a * b;            // Function returns the product of a and b }

The result in x will be:

12