for loops in 4 steps

A for loop is similar to a do or a while loop but much more compact. Typically used for actions that need to be run a particular amount of times. Also useful when working with arrays.

You should know at least a little bit about other loops in javascript before diving in given their many similarities.

Building a simple for loop…

1. Basic for loop structure

for loop bones

2. Add in variable. Usually displayed as a single letter given it is just a place counter. This will initialize the loop by defining a variable.

var i = 0;

3.Create a condition that checks to continue. As long as the value stored in i is < 10, the loop will run. As soon as value is 11, the loop is finished.

i < 10;

4.Finally you want to make sure the loop ends at some point by updating the state of the loop. Change the value of i each time through the loop.

i += 1

A while loop turned into a for loop..

Here’s an example of how while and for loops are related.

While Loop..

While Loop

Now lets get loopy, we’ll recreate this while loop as a for loop..

for loop

You can see how it is easy to create the same loop with less lines of code. Also, while we’re on the subject. Looper was a great movie.

//This is a barebones explanation and for loops can become very, very complex

//Newbie so if you have any additional insights, comment and I’ll update.