> For the complete documentation index, see [llms.txt](https://js201.gitbook.io/js-101/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://js201.gitbook.io/js-101/loops.md).

# Loops

Loops are repetitive conditions where one variable in the loop changes. Loops are handy, if you want to run the same code over and over again, each time with a different value.

Instead of writing:

```javascript
doThing(cars[0]);
doThing(cars[1]);
doThing(cars[2]);
doThing(cars[3]);
doThing(cars[4]);
```

You can write:

```javascript
for (var i = 0; i < cars.length; i++) {
  doThing(cars[i]);
}
```