Summary: Loops in JavaScript

Key points

• A loop is a block of code that runs over and over again until a certain condition is met.
• An infinite loop is a loop that never stops, because it’s impossible to meet the condition for breaking out of the loop.
• A while loop will continue to run as long as a particular condition is true.
• A do–while loop will also run while a condition is true, but the condition comes at the end, rather than the beginning of the loop.
• A for loop sets the initial value, a condition for stopping, and increment at the start, and then runs a block of code until the condition is met. After every loop, the increment instruction is carried out.
• Nested loops can be formed by running a loop within another loop. The inner loop runs all the way through for every pass of the outer loop.

In the next chapter, we’ll learn all about functions. But first, we have a quiz and a challenge!