JavaScript/CheatSheet

Data Types

var num = 8;                               // number
var strg = "Joe";                          // string
var vobj = {first: "John", last:"Doe"};    // object
var booli = false;                         // boolean
var arr = ["HTML","CSS","JS"];             // array
var a; typeof a;                           // undefined
var a = null;                              // value null

const pi = 3.14;

typeof strg                                // =string

Arrays

var title = new Array();
title[0] = "Mr.";
title[1] = "Mrs.";

concat()
filter()
forEach()
join()
map()
pop()
push()
reduce()
reverse()
shift()
slice()
splice()
sort()

Strings

charAt()
charCodeAt()
concat()
fromCharCode()
indexOf()
lastIndexOf()
match()
replace() 
search()
slice()
split()
substr()
substring()
toLowerCase()
toUpperCase()
valueOf()

Functions

function addition(number1, number2) {
  return number1 + number2;
}

Operators

+           Addition
-           Subtraction
*           Multiplication
/           Division
(...)       Grouping operator, operations within brackets are executed earlier than those outside
%           Modulus (remainder )
++          Increment numbers
--          Decrement numbers

==          Equal to
===         Equal value and equal type
!=          Not equal
!==         Not equal value or not equal type
>           Greater than
<           Less than
>=          Greater than or equal to
<=          Less than or equal to
?           Ternary operator

&&          Logical and
||          Logical or
!           Logical not

&           AND statement
|           OR statement
~           NOT
^           XOR
<<          Left shift
>>          Right shift
>>>         Zero fill right shift

if - else

if (condition) {
    // if condition is met
} else {
    // if condition is not met
}

Loops

for
while
do while
break
continue

Escape Characters

\'      Single quote
\"      Double quote

\\      Backslash
\b      Backspace
\f      Form feed
\n      New line
\r      Carriage return
\t      Horizontal tabulator
\v      Vertical tabulator