Javacript

Numbers

• Positive / Negative
• NaN is a number but is not avalue - isNaN()

Strings

• string literal can be between '' or ""
• escape character \
• Print to console - ''Hello World''
• Tab = \t
• Carriage Return = \r
• New line = \n

Strings cont...

• length property
• Concatenation

Booleans

• true / false

Empty Types

• null
• undefined

Variables

• var name = 1; // int / number
• var name2 = 'hi!'; // string

typeof

• what am i?

Type Conversion

console.log(8 * null)
// → 0
console.log("5" - 1)
// → 4
console.log("5" + 1)
// → 51
console.log("five" * 2)
// → NaN
console.log(false == 0)
// → true

Operators

• operators for arithmetic (+, -, *, /, and %)
• string concatenation (+)
• comparison (==, !=, ===, !==, <, >, <=, >=)
• logic (&&, ||)

Unary Operators

• - to negate a number
• ! to negate logically
• typeof to find a value’s type

Ternary Operator

• ? :

Conditionals

Controlling the flow of execution

If / Else

if (true){ } else { }

Else if

if (true){ } else if { } else {}

While

while () { }

Do While

do{} while()

Execute body once

For loop

for(var i =0; i < 100; i++) { }

break

for(var i =0; i < 100; i++) { break; }

counter shortcuts

• ++ / --
• += / -=

switch

switch(){ case "red": break; default: break; }

Functions

DRY - Dont repeat yourself

Creating Functions

function name() {} //moved to top

var name = function() {}

Scopes

global

local

Nested Scope

• inner can see outer
• outer cannot see inner

Arrow functions

• name = x => { do stuff }
• shorthand

Questions?