contents.md

Contents

1. Numbers, expressions and variables

2. Functions

3. Booleans and conditionals

4. Strings and interpolation

5. Arrays and for of

6. Objects and for in

7. Methods and this

8. Prototypes

9. Events and callbacks

10. Promises

11. Fetch

12. DOM

13. SVG

14. Canvas

15. Audio

16. D3 https://square.github.io/intro-to-d3/

Math

Expressions

If you type a number into the REPL, it'll echo it back to you. That's because the REPL always tells you what value is produced by an expression, and your number is a very simple mathematical expression.

Operators

You can do arithmetic in JavaScript the same way as you would with a paper and pen. 1 + 1 = 2. But in JavaScript we can just do the 1 + 1 part, and the interpreter computes 2.

Here are some math operators you're familiar with:

Operator	Name	Example	Output
+	add	2 + 2	4
-	subtract	2 - 2	0
*	multiply	2 * 2	4
/	divide	2 / 2	1
%	remainder	2 % 2	0

The only one that may need any explanation is remainder. The expression 2 % 2 gives you the remainder of two divided by two, 0.

Variables