Question

Suppose I have to write a javascript function:

function(){
    var a=1;
    var sum=1;
    for(var i=0;i<6;i++){
        sum=sum+a+1;
    }
    console.log(sum);
}

Someone recommended me to write this function like this:

function () {

   var a = 1;
   var sum = 1;
   for (var i = 0; i < 6; i++) {
      var sum = sum + a +1;
   }
   console.log(sum);

}

With more blank space, I know this rule, but I don’t how it works, or what can I benefit from it?

Answer 1

It is a matter of opinion what good style is, but in a general sense picking some style and consistently following it throughout your code makes it easier to read (both for other people and for you when you come back to it later).

In my experience most people find code easier to read with the extra spaces as shown in your second example.

I don’t like putting a space between function and (). Or, where there is a function name I don’t put a space between the name and the parentheses: function someName().

Note also that with modern code editors that have syntax highlighting (like Stack Overflow does) it is much easier than it used to be to read code that doesn’t have spaces. Compare the following two:

for(var i=0;i<6;i++)

for(var i=0;i<6;i++)

Reading and editing the latter, all in black and white, really annoys me, but I don’t mind the coloured version anywhere near as much. I still prefer it with the extra spaces though.

I’d make some other changes in your function:

function() {
    var a = 1,
        sum = 1,
        i;

    for(i = 0; i < 6; i++){
       sum += a + 1;
    }
    console.log(sum);
}