Data Types

• As far as data types are concerned JavaScript provides us 3 basic data types which are chosen based on the value assigned to the variable.
• These 3 data types are:

1. String
2. Number
3. Boolean

String Data Type

1. A String is just a combination of words including nos.
2. Any type of character can be stored in a string.
3. It is enclosed in “    “  or ‘     ‘ .

For Example

var myName=“Nishant”;

OR

var myName=‘Nishant’;

Printing Double Quotess

To print double quoted string we have 2 ways:

 

For Example

a. var msg=“  \”Hello\”   “;

OR

b. var msg=‘  “Hello”  ‘;

Number Data Type

Numbers in JavaScript are just numbers , no integers and no floats , just plain numbers

For Example

var salary=40000;

var pie=3.14;

var phoneBill=2000;

 

Boolean Data Type

Booleans can only have two values: true or false.

 

For Example

var x=true;
var y=false;

Booleans are often used in conditional testing.

 

// declaring one javascript variable

var firstName;

// declaring multiple javascript variables

var firstName, lastName;

// declaring and assigning one javascript variable

var firstName = ‘Nishant’;

// declaring and assigning multiple javascript variables

var firstName = ‘Sachin’, lastName = ‘Gupta’;

Variables Decl Rules

1. Variable names must begin with a letter and can have digits also.
2. Variable names can also begin with $ and _
3. Variable names are case sensitive
   Default value of a variable is “undefined”