Declaring multiple variables in JavaScript

javascript variables coding-style performance declaration
Steve Harrison picture Steve Harrison · Mar 29, 2009 · Viewed 323.6k times · Source

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

var variable1 = "Hello, World!";
var variable2 = "Testing...";
var variable3 = 42;

...or like this:

var variable1 = "Hello, World!",
    variable2 = "Testing...",
    variable3 = 42;

Is one method better/faster than the other?

Answer

Jeremy Ruten picture Jeremy Ruten · Mar 29, 2009

The first way is easier to maintain. Each declaration is a single statement on a single line, so you can easily add, remove, and reorder the declarations.

With the second way, it is annoying to remove the first or last declaration because they start from the var keyword and finish with the semicolon respectively. Every time you add a new declaration, you have to replace the semicolon in the last old line with a comma.

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