Is it true that I should use K&R styling when writing javascript? [closed]

Question

I didn't realise it until recently, but I use the Allman style when writing javascript code.

According to http://encosia.com/in-javascript-curly-brace-placement-matters-an-example/ I should be using K&R style. This is because in some situations placement of the curly bracket on the next line can cause problems. The problem for me is that I've grown rather fond of the Allman style and would rather not change.

So, my question(s)

• Is it true that the allman style can cause errors due to the placement of curly brackets in javascript? How about jquery?

• Is there any trick that would enable me to use Allman style without problems due to curly brackets?

• Are there any other problems associated with using these styles?

Answer 1

Is it true that the allman style can cause errors due to the placement of curly brackets in javascript?

Yes, it is. As your link explains, return statements followed by a newline will confuse the parser as it tries to insert a semicolon. This behavior is not limited to returning object literals, though. The following function:

function foo()
{
    return
        "bar";
}

Will also return undefined.

How about jquery?

The situation remains exactly the same whether or not jQuery is included.

Is there any trick that would enable me to use Allman style without problems due to curly brackets?

Yes, do not use Allman style with object literals. Consider you want to assign an object literal to a variable. Are you really going to write:

var foo =
{
    bar: "quux"
};

Or will you go for:

var foo = {
    bar: "quux"
};

IMHO the second snippet is more readable than the first. You can continue using Allman style with the braces inside for, if, while, function, etc., but make an exception for object literals.

Are there any other problems associated with using these styles?

return is quite a special case, because it is valid with or without an argument. When confronted with a lone return statement on one line, the parser cannot tell if it should add a semicolon to make the single-line statement valid, or continue to the next lines and hope for the best.

For this reason, I think this behavior only becomes a problem with return and maybe throw, not other statements.

Answer 2

Keep in mind ECMAScript specification regarding automatic semicolon insertion:

Certain ECMAScript statements (empty statement, variable statement, expression statement, do-while statement, continue statement, break statement, return statement, and throw statement) must be terminated with semicolons. Such semicolons may always appear explicitly in the source text. For convenience, however, such semicolons may be omitted from the source text in certain situations. These situations are described by saying that semicolons are automatically inserted into the source code token stream in those situations.

I laugh at the suggestion above that it is "convenient"...

While you technically could could continue using Allman formatting in cases not covered above, I would preach consistency. Personally I'm a fan of Google JS styleguide - sections relevant to your question are the code formatting and semicolons ones. The examples listed there are worth checking out.