Codecademy

Control Flow

01/08

Although you should be familiar with most of this, let's quickly review the syntax of some common JS control flow.

Here's an example of an if statement that uses else if and else.

Try modifying this to test if a variable is undefined or null.

Instructions

Each lesson starts here. Read the explanation, then follow the instructions underneath. If you get stuck, you can click on the "Hint" for help.

Type your response to the instructions here, in your code editor.

Ready to see if your code does what it should? Click "Save + Submit" to run and check your code!

Click "Save + Submit" to run your code! Your code’s output will pop up on the screen.

This is the terminal. When you submit your code, it will run your code and display the result here.