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JavaScript

Learn JavaScript from basics to advanced concepts.

1

Hello World

Every programmer’s journey begins with “Hello, World!”. In JavaScript, we use console.log() to print output to the console.

Example

Run this example to see how it works and then try the exercise.

example.js
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Output
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Exercise

Your task: Print "Hello, World!" to the console

main.js
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Output
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Quiz

Which method is used to print output to the console in JavaScript?

SUMMARY

In this section, you learned how to print output to the console. Next, you’ll learn how to declare variables using let and const.

2

Variables with let and const

Variables store data. Use let for values that change and const for constants that stay the same.

Example

Run this example to see how it works and then try the exercise.

example.js
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Output
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Exercise

Your task: Create two variables: greeting and name

main.js
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Output
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Quiz

What keyword should you use for a variable that will never change?

SUMMARY

In this section, you learned how to declare variables using let and const. Next, you’ll learn how to perform mathematical operations.

3

Arithmetic Operations

JavaScript supports standard arithmetic operators with specific precedence rules.

Example

Run this example to see how it works and then try the exercise.

example.js
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Output
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Exercise

Your task: Calculate the area of a rectangle

main.js
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Output
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Quiz

What is the result of 10 + 5 * 2 in JavaScript?

SUMMARY

In this section, you learned how to perform mathematical operations. Next, you’ll learn how to manipulate and work with strings.

Unlock 10 More Lessons

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Locked lessons:
  • String Operations
  • Conditionals
  • If-Else
  • While Loops
  • Functions
  • Arrays
  • Objects
  • Array Methods: map, filter, reduce
  • Final Project: Task Manager
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