Declaring multiple variables in JavaScript

Question

In JavaScript, it is possible to declare multiple variables like this:

var variable1 = "Hello, World!";
var variable2 = "Testing...";
var          


        

Answer 1

Besides maintainability, the first way eliminates possibility of accident global variables creation:

(function () {
var variable1 = "Hello, World!" // Semicolon is missed out accidentally
var variable2 = "Testing..."; // Still a local variable
var variable3 = 42;
}());

While the second way is less forgiving:

(function () {
var variable1 = "Hello, World!" // Comma is missed out accidentally
    variable2 = "Testing...", // Becomes a global variable
    variable3 = 42; // A global variable as well
}());