Start learning free

LESSON 136 OF 671 · FOR LOOPS - LOOPING OVER ARRAYS

For Loops in JavaScript

Lesson

A for loop is a special type of loop in JavaScript which allows us to loop over the items of a collection, such as a string or an array.


Looping through a string:

For example, a string is a sequence of characters, so we can use a for loop to iterate over each character and do something with that character:

let name = "Andy";

for(let letter of name) {
  console.log(letter);
}

Let's break down this code:

  • The for keyword that indicates the start of a for loop.
  • letter is the loop variable. It will take the value of each different item in the collection
  • The of keyword separates the loop variable from the collection we will iterate on
  • name is the collection to loop over

The output of this code is:

A
n
d
y

As you can see, on each iteration, letter was assigned the value of the next item in the string and inside the loop, we printed that value.


Looping through an array:

We can also use for loops with lists:

let fruits = ["banana", "orange", "pear", "kivi"];

for (let fruit of fruits) {
  console.log("I eat " + fruit);
}

The output of this code is:

I eat banana
I eat orange
I eat pear
I eat kivi

Assignment
Now let's greet our friends using a for loop!


Hint
Look at the examples above if you get stuck.


STEP 1 OF 2
    Ctrl + Enter to check