JavaScript braces on new line or not? [closed]

Answer 1

I prefer the K&R method for the same reasons listed above. It looks more compact, and the two relevant lines are grouped together.

Answer 2

Douglas Crockford gives a reason for choosing the K&R style¹:

I always use the K&R style, putting the { at the end of a line instead of the front, because it avoids a horrible design blunder in JavaScript's return statement.

The blunder he is referring to is how JavaScript handles the return statement differently in the following two scenarios:

return {
   'status': 'ok'
};

... and:

return 
{
   'status': 'ok'
};

The first one will return an object with a status property, while the latter will return undefined because of semicolon insertion.

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¹ Douglas Crockford: JavaScript: The Good Parts: Style (page 96) - ISBN: 978-0596517748.

Answer 3

In my opinion, it depends on who else will be working with your code. If you work on a C# team and share a lot of responsibilities, put it on a new line and avoid the inevitable bickering that would otherwise follow. If you work with a lot of PHP (or older JS programmers), put it on the first line for the exact same reason.

But if you're looking for something more authoritative, Douglas Crockford says that the opening brace should always be on the top line. His reasoning, if I remember correctly, is that it makes it consistent with the rest of the language. Basically, because this is valid but (probably) incorrect code:

function myFunc() 
{
    return 
    {
      ok: true
    };
} 

...you should universally avoid putting open-braces on a new line. Why? Because programming style should not lead to syntactic ambiguity.

The sample code above is valid because it is completely syntactically correct and no exceptions will be raised if you write this. However, instead of returning an object literal, {ok:true}, it will return undefined and the code below it will not be reached. Put the opening braces up one line and it will return the object literal you were, perhaps, expecting.

The question is, do you find that argument compelling enough?

Answer 4

Neither one is better than the other. Just choose one and use it consistently.

Answer 5

As stated in many answers, its mostly important that you find a style that you (and/or your team mates, if applicable) stick to. Personally I prefer same line as I've found that putting curly braces on the new line can lead to lots of near blank lines if you're working with closures and nested functions, which makes code less readable for me (although, probably not for most people...)

Answer 6

I follow Douglas Crockford's JavaScript coding convention, which was inspired by Sun's Java style guidelines.

Here's a link to it: http://javascript.crockford.com/code.html