Closure or Bind

Question

Is there any difference between limiter 1 and limiter 2?

var limiter1 = function(limiter){
   return function(item){
      return item > limiter;
   };    
};
var limiter2 = function(limiter){
   return function(limiter,item){
      return item > limiter;
   }.bind(this,limiter);
};

score 1 · Accepted Answer · answered Dec 18 '15 at 16:21

1

In most cases, they will function identically. However...

If you ever start to actually use the value of this, the function returned by limiter1 will be unbound (so a consumer could change the value with a call to Function.prototype.bind). In limiter2, it's locked down with the initial bind call.

Also, they use different levels of scope to get the limiter variable. Depending on the engine, you could have a (minute) difference in performance.

answered Dec 18 '15 at 16:21

TbWill4321

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And witch one would be the faster in that case? – Gel Dec 18 '15 at 16:26
There is no single case, and it's so small that you would be wasting your time optimizing in 99.9% of the cases. – TbWill4321 Dec 18 '15 at 16:27

score 0 · Answer 2 · edited May 23 '17 at 12:07

0

The .bind algorithm is a lot more complicated than wrapping a function with another function. However, most of the time it does not matter. I think that using native .bind usually provides for more readable and maintainable code - which is a big plus.

You can see more about this Why is bind slower than a closure?

edited May 23 '17 at 12:07

Community

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1

answered Dec 18 '15 at 16:54

Hernan C. Vazquez

166
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I think if I already have the wrapped function(so it's not an anonymous), than I must use the bind method, but if I create the function on the fly than the bind method become unnecessarily. – Gel Dec 19 '15 at 10:25
Yes, I agree with that. – Hernan C. Vazquez Dec 20 '15 at 00:53

Closure or Bind

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