Full Stack Web Development MASTERY Course - Novice to Expert - Callback Functions in JavaScript

This tutorial explains callback functions in JavaScript, their importance, and how to use them. It covers the concept of higher-order functions, asynchronous execution, and provides a practical example using the setTimeout function to demonstrate how callbacks work. The tutorial emphasizes the need to call functions for them to execute and highlights the role of callbacks in preventing errors in asynchronous code.

What is a callback function in JavaScript?

• A function that is executed after another function has finished executing.

• A function that is executed before another function starts.

• A function that is always executed synchronously.

• A function that cannot be passed as an argument.

Why are callback functions important in JavaScript?

• They allow JavaScript to execute code synchronously.

• They help in handling asynchronous operations efficiently.

• They are used to declare variables.

• They prevent JavaScript from executing any code.

What does JavaScript's execution order typically follow?

• Top to bottom

• Inside out

• Bottom to top

• Random order

How can you ensure a function executes after a task is completed in JavaScript?

• By using a loop

• By using a callback function

• By using a variable

• By declaring the function globally

What is the purpose of the setTimeout function in JavaScript?

• To execute a function immediately

• To delay the execution of a function

• To stop the execution of a function

• To execute a function in a loop

What must you do to ensure a function executes in JavaScript?

• Comment the function

• Call the function

• Ignore the function

• Declare the function

What happens if you don't call a function in JavaScript?

• The function will cause an error

• The function will execute twice

• The function will not execute

• The function will execute automatically