# Chapter 10 Iteration

Every time some operations have to be repeated, a loop may come in handy. Loops are good for:

• Doing something for every element of an object;
• Doing something until the processed data runs out;
• Doing something for every file in a folder;
• Doing something that can fail, until it succeeds;
• Iterating a calculation until it reaches convergence.

Here, we will learn the following types of iteration statements:

for() {}
while() {}
repeat {}

We will also dive into the apply() family functions, which are interesting function-based alternatives to for() {} loops.

We will finally learn about two special statements that allow us to control iterations:

break
next