Which JavaScript Loop Do You Use the Most and Why?

#discuss #javascript #programming #webdev

JavaScript gives us multiple ways to loop through data and execute repetitive tasks, each with its own strengths and ideal use cases:

for, while, do...while
for...in, for...of
.forEach(), .map(), .filter(), .reduce()

👉 Which one do you reach for the most in your projects?

Top comments (17)

Rense Bakker • May 18

Tbh I barely use just loops anymore. It's almost always .map in combination with filter or reduce if needed. If mapping is not required I use forEach or for of depending on where the data comes from. If the data comes from a source outside of the source code, I always use for of for performance reasons. Oh and sometimes while loops when doing recursive stuff, like with generator functions.

Shariful Ehasan • May 22

Using .map, .filter, and .reduce definitely leads to more declarative and readable code in most cases.

Bassel Al-Sayed • May 22

I don't use reduce anymore, instead I've adopted the habit of using Object.fromEntries:

const customEventNames = ['click', 'pageload', 'unmount'];

// before
const customEvents = customEventNames.reduce((acc, name) => {
  acc[name] = new CustomEvent(name);
  return acc;
}, {});

// after
const custmomEvents = Object.fromEntries(
  customEventNames.map((name) => [name, new CustomEvent(name)])
);

I used to think using reduce was very fancy, imo now this is so much cleaner

Shariful Ehasan • May 22

reduce can be powerful but often feels a bit cryptic for building objects. Object.fromEntries + map is way more readable, especially for teammates going through your code later. Nice switch! 👌

𒎏Wii 🏳️‍⚧️ • May 18

for (const item of collection) {} is the way to go :)

Mike Talbot ⭐ • May 18

for or for...of if I'm looking for speed. map, then filter, then reduce by the look of things for data manipulation.

Nevo David • May 18

nice, i always default to forEach out of habit but maybe i should branch out more - you ever feel like certain habits just stick even when you know there’s other options around?