In JavaScript, when declaring multiple variables at once are there memory benefits to using only one var statement?

Question

For Example,

//pattern one
function Foo() {

    var hello
        , world
        , how = []
        , are
        , you = 'you';
}

//pattern two 
function Foo() {

    var hello;
    var world;
    var how = [];
    var are;
    var you = 'you';
}

Would it be more memory efficient to use pattern one, versus pattern 2? Are there other benefits one provides over the other?

Matthew Flaschen · Accepted Answer · 2012-06-01 15:47:01Z

4

No, they're both exactly the same. Some people prefer doing all variable declarations at the top of the function, because that's where they effectively are due to hoisting. JSLint also has an option to require a single var statement (onevar), but I really don't find that necessary.

answered Jun 1, 2012 at 15:47

Matthew Flaschen

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MaxArt · Accepted Answer · 2012-06-01 15:47:04Z

2

No. It's just a matter of code readability.

answered Jun 1, 2012 at 15:47

MaxArt

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sree · Accepted Answer · 2012-06-01 15:50:08Z

1

memory allocation is done internally using different memory locations (storage wise), therefore it really does not make difference to use with a single declaration or multiple declaration.

answered Jun 1, 2012 at 15:50

sree

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