Confused about the JS best practices with Length property in the For Loop?

Question

function printList ( list ) {

var listHTML = '<ol>'; 

for ( var i = 0; i < list.length; i += 1) {  
    listHTML +='<li>' + list[i] + '</li>'; 
}

listHTML += '</ol>'; 

}

Before watching this video I had come across this link (https://www.w3.org/wiki/JavaScript_best_practices)

And then I watched this video which seems to go against what is written in Section 12 "Optimize Loops" .

hmm so I am a little lost as to which practice I should stick too. Since I am just learning I am not 100 percent sure, but should I follow the recommendation on the link and Always declare the array length property in a separate variable instead of directly in the For loop to save on memory? Just asking since he did not do it in the video ?

Answer 1 · 2017-07-31T09:08:43Z

July 31, 2017 9:08am

I found it amusing that other examples in the same article (such as the one for #8 - Modularize) did not follow this "best practice".

I'm not sure I'd call this a "best practice" but I would recommend keeping it in mind for optimizing compute-heavy tasks. I did some benchmark tests and found that it can reduce running time by 5-13%, depending on the array size.

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ian izaguirre

ian izaguirre

Confused about the JS best practices with Length property in the For Loop?

1 Answer

Steven Parker

Steven Parker

ian izaguirre

ian izaguirre

ian izaguirre

ian izaguirre

Steven Parker

Steven Parker