- 11.1 Don't use iterators. Prefer JavaScript's higher-order functions like
map()
andreduce()
instead of loops likefor-of
.
Why? This enforces our immutable rule. Dealing with pure functions that return values is easier to reason about than side-effects.
const numbers = [1, 2, 3, 4, 5];
// bad
let sum = 0;
for (let num of numbers) {
sum += num;
}
sum === 15;
// good
let sum = 0;
numbers.forEach((num) => sum += num);
sum === 15;
// best (use the functional force)
const sum = numbers.reduce((total, num) => total + num, 0);
sum === 15;
- 11.2 Don't use generators for now.
Why? They don't transpile well to ES5.