The 3 for statements
There are 3 ways to iterate through an array with for
loops:
- With the simple
for
loop. -
With the
for...of
loop, which works with any iterable object. Arrays are iterable objects. -
With the
for...in
loop, which works with any object. Arrays are objects that happen to have integer-like strings as keys (or property names).
Note that the for...of
statement iterates through the elements of the array
while the for...in
` statement iterates through the property names (or keys) of the array, which are its indices.
Example
const array = [1, 2, 3, 4, 5];
// Simple for loop
for (let i = 0; i < array.length; i += 1) {
console.log(array[i]);
}
// for...of loop
for (let num of array) {
console.log(num);
}
// for...in loop
for (let i in array) {
console.log(array[i]);
}
Practice and remember
You can now test you level of expertise with JS arrays.