Javascript Variables

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.