Every programmer’s journey begins with “Hello, World!”. In JavaScript, we use console.log() to print output to the console.
JavaScript
Learn JavaScript from basics to advanced concepts.
1
Hello World
Example
Run this example to see how it works and then try the exercise.
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Output
Click "Run" to see the example in action...Exercise
Your task: Print "Hello, World!" to the console
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Output
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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.
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Output
Click "Run" to see the example in action...Exercise
Your task: Create two variables: greeting and name
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Output
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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.
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Output
Click "Run" to see the example in action...Exercise
Your task: Calculate the area of a rectangle
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Output
Click "Run" to execute your code...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
- For Loops
- While Loops
- Functions
- Arrays
- Objects
- Array Methods: map, filter, reduce
- Final Project: Task Manager