JavaScript Cheat sheet Superior programmer
JavaScript cheat sheets will work as memory refreshing tools while developing a website. A JavaScript cheat sheet provides simple, brief instruction for executing JavaScript on a web page.It will help you to get started with JavaScript and let you know what all the things you can do with it. Here at Template’s website builder. Let’s explore some of the best JavaScript cheat sheets listed below.
Combine elements of an array into a single string and return the string
Functions
function name(parameter1, parameter2, parameter3){//what the function does}
If/ Else
if (condition) {
//what to do if condition is met
}else {
//what to do if condition is not met
}
Objects
var person ={
firstName: “John”,
lastName: “Doe”,
age:20,
nationality:”German”
};
Variables
var a; // variable
var b = “init” // string
var c = “Hi” + ” ” +” Joe” // Hi Joe
var d= 1 + 2+”3″ // “33”
var e = [2,3,4,5] // array
var f = false // boolean
Const PI = 3.14 //constant
var a = 1, b = 2, // one line
let z = ‘zzz’ // block scope
Var, let
Can be reassigned
Const
Cannot be reassigned
Basics
On Page Script
<script type = “text/javascript”> … </script>
Comments
//
Single line comments
/* Comment here * /
Multi-line comments
Edit Dom Element
document.get ElementbyId(“element ID”).innerHTML=”Hello World”;
Arrays
var fruits = [“Banana”, “Apple”, “Pear”];
Array Methods
fruits.shift()
Remove the first element of an array
fruits.slice ()
Pulls a copy of a portion of an array into a new array of 4 24
fruits.sort()
Sorts elements alphabetically
fruits.splice()
Adds elements in a specified way and position
fruits.toString()
Converts elements to strings
fruits.unshift()
Adds a new element to the beginning
fruits.valueOf()
Returns the primitive value of the specified object
Loops
for (before loop; condition for loop; execute after loop) {//what to do during the loop}
for – The most common way to create a loop in JavaScript while – Sets up conditions under which a loop executes
do while _ Similar to the while loop but it executes at least once and performs a check at the end to see if the condition is met to execute again
break _ Used to stop and exit the cycle at certain conditions
continue _ Skip parts of the cycle if certain conditions are met
Operators
Basic Operator
+ Addition
– Subtraction
* Multiplication
/ Division
() Grouping operator
% Modulus (remainder)
++ increment numbers
– – Decrement numbers
Bitwise Operators
& AND Statement
I OR statement
~ NOT
^ XOR
« Left shift
» Right shift
>>> Zero fill right shift
Comparison Operators
= = Equal to
= = = Equal value & type
! = Not equal
!= =Not equal value/type
> Greater than
< Less than
>/ Greater than or equal to
</ Less than or equal to
? Ternary operator
Events
Mouse
onclick, oncontextmenu, ondblclick, onmousedown,onmouseenter,
onmouseleave, onmousemove,onmouseover, onmouseout, onmouseup.
Keyboard
onkeydown, onkeypress, onkeyup
Frame
onabort, onbeforeunload, onerror,onhashchange, onload, onpagehide, onpageshow, onresize, onscroll
Drag
ondrag, ondragend, ondragenter, ondragleave, ondragover, ondragstart, ondrop
Clipboard
oncopy, oncut, onpaste
Media
onabort, onended, onerror, onpause, onplay, onplaying, onvolumechange, onseeking, onratechange
Array Methods
fruits.concat ()
Join several arrays into one
fruits.index0f ()
Returns the first position at which a given element appears in an array
fruits .join()
Combine elements of an array into a single string and return the string
fruits.lastIndexOf()
Gives the last position at which a given element appears in an array
fruits.push()
Add a new element at the end
fruits.reverse()
Reverse the order of the elements in an array
