Variables in Javascript

Variables in javascript

Variables in javascript

  • A variable is a name which holds a value in the computer memory.
  • Javascript is a dynamic typed language. It means we do not define the types while defning a varialbe unlike the statically typed languages.
  • We can store different data types in the variable

Examples for javascript variables

Number variables

let ten = 10;
let weight = 55.5;

String variables

let firstName = "Anjaneyulu";
let lastName = "Batta";

Object variables

let student = {
    firstName: "Anjaneyulu",
    lastName: "Batta",
    age: 20,
    weight: 68,
}

let numbers = [1, 2, 3, 4, 5.5]

Points to remember when you are defining a javascript variable

  • Variable names cannot contain spaces.
  • Variable names must begin with a letter, an underscore (_) or a dollar sign ($).
  • Variable names can only contain letters, numbers, underscores, or dollar signs.
  • Variable names are case-sensitive(i.e uppercase letters and lowercase letters are not cosidered as same).
  • Do not use in-build javascript variables or reserved words.
  • Variable should be meaningful & it should represent the information about data stored in it.
  • variable name should not be too small or too lengthy
  • When you have multiple words in the variable then you can use the camelcase notation or underscore(_) notation.
  • Examples: firstName, full_address, collegeName, address1, address2

Javascript Reserved Keywords

  • JavaScript has some reserved words you should know before you begin coding. The following table contains a list of JavaScript reserved words, which cannot be used as JavaScript variables, functions, methods, loop labels, or object names.
abstract boolean break byte case catch
char class const continue debugger default
delete do double else enum export
extends false final finally float for
function goto if implements import in
instanceof int interface long native new
null package private protected public return
short static super switch synchronized this
throw throws transient true try typeof
var void volatile while with