Chapter 7

Function Expressions

WHAT’S IN THIS CHAPTER?

• Function expression characteristics
• Recursion with functions
• Private variables using closures

One of the more powerful, and often confusing, parts of JavaScript is function expressions. As mentioned in Chapter 5, there are two ways to define a function: by function declaration and by function expression. The first, function declaration, has the following form:

function functionName(arg0, arg1, arg2) {
    //function body
}

The name of the function follows the function keyword, and this is how the function’s name is assigned. Firefox, Safari, Chrome, and Opera all feature a nonstandard name property on functions exposing the assigned name. This value is always equivalent to the identifier that immediately follows the function keyword: