Variables & Types

Data Types

Numeric Types

// Integer
123
-456

// Float
123.45
-0.5

// Long (ends with L)
123456789L

Strings

// Single quotes
'hello world'

// Double quotes
"hello world"

// Template strings (with interpolation)
`Hello ${name}`
`Value is ${1 + 2}`

// Escape characters
'a\'b'      // a'b
`1\`2`      // 1`2

Boolean

true
false

Null

null

Variable Declaration

var x = 10;      // Function scope
let y = 20;      // Block scope
const PI = 3.14; // Constant

// Uninitialized declaration
var a;
let b;

Assignment

x = 15;
obj.prop = 100;
arr[0] = 'first';

Delete

delete x;
delete obj.property;

Type Conversion

Function	Description
parseInt(s)	Parse integer
parseFloat(s)	Parse float
typeof(x)	Get type