Intro to JavaScript

What you will learn

• Script loading and the console
• const, let and the primitive types
• Type conversion
• Strings and template literals
• Operators and equality
• if, switch and truthiness
• alert, confirm and prompt
• Arrays and objects
• Loops

Lessons

1. 1

   JavaScript and the Browser

   What runs your JavaScript, the tools you use, console.log, and how a page loads a script.

   12 exercises

2. 2

   Variables and Types

   Declare with const and let, finish a function, meet the primitive types and convert between them on purpose.

   13 exercises

3. 3

   Strings

   Quotes and escapes, template literals, the + trap, indexes and slices, and the everyday string methods.

   11 exercises

4. 4

   Operators

   Arithmetic and compound assignment, === versus ==, comparing text, &&, || and ??, the ternary and precedence.

   11 exercises

5. 5

   Decisions and User Input

   if, else if and nested conditions, truthy and falsy values, switch with break, and alert, confirm and prompt.

   11 exercises

6. 6

   Arrays and Objects

   Arrays and their everyday methods, which ones change the array, and objects as records with dot and bracket access.

   11 exercises

7. 7

   Loops

   while and do...while, the counting for loop and off-by-one, for...of and for...in, and break and continue.

   11 exercises

8. 8

   Putting It Together

   Plan a program from its contract, then build a cart with tax tiers, a grade report, a word counter, FizzBuzz and a password checker.

   8 exercises

How you practice

You practice in the browser and every exercise gives you feedback right away. This course uses these formats:

• Code exercise: 29
• Fix the bug: 17
• Predict the output: 14
• Type the answer: 9
• Fill in the blank: 7
• Multiple choice: 4
• Spot the bug: 3
• Match the pairs: 2
• Select all that apply: 2
• Reorder lines: 1