My attempt: function reverseStr(str) { let newStr = str.split(''); ...

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Replies for: I think something like this would actually be the most performant: function reverseStr(str){ let newStr = "" for (let i = str.length-1; i &g...

My attempt:

function reverseStr(str) {
    let newStr = str.split('');

    for (let j = str.length - 1, i = 0; i < j; i++, j--) {
        let temp = newStr[i];
        newStr[i] = newStr[j];
        newStr[j] = temp;
    }

    return newStr.join('');
}

Никита Сковорода • Nov 28 '18 • Edited

That basically reimplements Array#reverse() from JS land at the second step.

Array#reverse() operates in-place, so there is no benefit here — you are doing exactly what .reverse() already does.

This approach is unlikely to be more performant than the built-in method, and just takes more code to write and maintain.

Thibault ROHMER • Nov 28 '18

Yep. Also remember your usage scenario.
Are you in a browser ?
How large is the string ?
How many strings ?

Because if you're only reversing a 100 chars string, even 1000 chars, the implementation (amongst thoses proposed in this thread) doesn't matter much performance wise (memory, duration, cpu cycles)...
For clarity and code comprehension, it's something else sure ^{^}

Theofanis Despoudis • Nov 29 '18

This is a showcase, not a contest. Also, there is no point using reverse() to do a reverse operation. It's the same as trying to explain some term using the same term in a sentence.

Meghan (she/her) • Nov 29 '18

This would be best solution. Yes it’s a re implementation of array reverse but it skips the split and join and only uses 2 bytes of memory and n/2 time

Meghan (she/her) • Nov 29 '18

Oh it’s not what I thought it was