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Discussion on: Stop using for loops. Here's why.

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matgott profile image
matgott

Try yourself.

let arr = [];
for(x = 0; x < 100000; x++) {arr.push(Math.random());}

function oldFor(d) {
aux = [];
const t0 = performance.now();
for(x=0; x < d.length; x++) {
aux.push(d);
}
return (performance.now() - t0);
}

function eachFor(d) {
let aux = [];
const t0 = performance.now();
d.forEach(v => {
aux.push(v);
});
return (performance.now() - t0);
}

oldFor(arr);
eachFor(arr);

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joey542 profile image
joey542

Okay. This is your code in typescript with a 10M length array. The forEach time is double.
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I made another for just testing the other loops with a 10M length array.
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So... the conclusion is... If you want to loop through big arrays just use the old for loop. And I made an account just for to send this comment.