Order of operations

Brackets (Technically parenthesis in js) Exponents ** in js Division Multiplication Subtraction

if statement

if (condition) { block - if first condition is true the others will never run } else if (another condition){ block } else if { block } else { nothin is true }

regex - always starts and closes with a / /\s/g, '-' - find space(\s), all of them(/g), and replace with -

Instead of an if else, you can just return out of the function that's running

Operators: == checks values but not type - use to check if a value is null or undefined === checks value and type - Use this the majority of the time !== not equal - type and value Greatet than >, less than < only ever work no numbers not strings - will convert to number if a string || or - in a succession of || only on true is needed to make the whole statement true && and - in a succession of && one false will make the whole statement false Breaking things out into variable and checking if(myVar) can make statement much more readable

Truthy values: 1 -10 Full string "0" - any string with content empty array empty object

Falsy values: 0 undefinded null NaN

Use .length to check if something is in an array use Object.keys({}).length

if-statements.js

! in front of bool always flips it - also forces(coerces) var type to bool !! coerces into a real boolean

Ternary - Shorthand if

1. condition
2. what to do if true
3. what to do if false

See intervals-cs.html