return with parentheses and without gets different results [duplicate]

Question

I met with some strange, in my opinion, behaviour. I think I don't understand what is going on, so if anyone can help me with this ... I will be glad.

function dateString1(date) {
return (
    ('0' + date.getDate()).slice(-2) + '/' +
    ('0' + (date.getMonth()+1)).slice(-2) + '/' +
    date.getFullYear()
);
}


function dateString2(date) {
return 
    ('0' + date.getDate()).slice(-2) + '/' +
    ('0' + (date.getMonth()+1)).slice(-2) + '/' +
    date.getFullYear()
;
}

so, dateString1 will return the string I'm looking for, but dateString2 will return undefined. Checked it on Chrome and IE8.

What's going on?

Thanks

Answer 1

Putting anything on a new line in JS is a stupid idea, for this very reason. Automatic semi-colon insertion is killing your code, return; is how the JS engine will interpret your code (which by itself is a valid statement). Put it like this:

function dateString2(date) {
    return ('0' + date.getDate()).slice(-2) + '/' +
    ('0' + (date.getMonth()+1)).slice(-2) + '/' +
    date.getFullYear();
}

Stay away from things like this:

if (something)
{
    // logic
}

And always use this style:

if (something) {
    // logic
}