🔁JS array looping
There are a few different ways to loop over an array:
for
for (var i = 0; i < array.length; i++) {
array[i]
}
forEach
array.forEach(function (i) {
array[i]
})
for in
for (var i in array) {
array[i]
}
for..of
for (var i of array) {
array[i]
}
Test results
| Test case name | Result |
|---|---|
| for | for x 4,680,671 ops/sec ±0.42% (68 runs sampled) |
| forEach | forEach x 5,043,765 ops/sec ±0.60% (67 runs sampled) |
| for in | for in x 9,155,750 ops/sec ±0.50% (68 runs sampled) |
| for..of | for..of x 1,339,234 ops/sec ±0.42% (68 runs sampled) |
for...of uses @iterators internally which aren’t as efficient