data types of javascript

Javascript datatypes :

To use any data its imp to know type of that data
JavaScript has dynamic types of data. means that the same variable can be used to hold different data types: var x = 12 ; var x = “ankit” ;
Javascript is a dynamic typing language, Javascript engine (chrome - v8, IE - chakra, Firefox - Spidermonkey.) automatically decides what type of variable is based on the value assigned to it.

Coercion :

Coercion is to convert one type to another with or without your awareness. Coercion happens when operands are of different types:
For instance: 1+ ‘2’ , returns text ’12’. Javascript converts number 1 to string ‘1’ and concat with string ‘2’.

Data Types :

“typeof” keyword is used to get type of any data/variable

Ex : var a = true; console.log(typeof a);

5) boolean :

Ex : var a = true; console.log(typeof a); => boolean

1) Null :

Null only contains one value null
Datatype of null is object
Until you do not specifically assign null to any variable Variable will not be null

Ex : var b = null; console.log("b", typeof b); => object

2) undefined :

Variable which does not have value called as undefined values
In JavaScript, a variable without a value, has the value undefined. The type is also undefined.

undefined and null are equal in value but different in type: typeof undefined => undefined typeof null => object

console.log(null === undefined) => false console.log(null == undefined) => true

4) number :

Largest javascript number is +infinity and smallest in -infinity
If you divide any number(positive/negative) with 0 you will get (+infinity/-infinity)
NAN( not a number) - shows you a some computational error, ex : if you devices nun number t number gives error of NAN it is result of incorrect mathematical error, if you get this start checking datatype of variables

Ex : var x = 12;

3) string : represents a textuals data

Ex : var x = “chrome”;

6) object :

always contain keys and values,
JavaScript objects are written with curly braces {}.
Object are written as name:value pairs, separated by commas.
Mostly property:value of single thing(1 car , 1 student ) Ex : var employee = {name : ”ankit” , age : 26, gender : “male”}

7) array :

contains only value/bunch of value,
Mostly contains value of multiple object(ex : names of 100 students, ) Ex var empName = [“ankit”,”rakesh”,”manoj”];
Array items are separated by commas.
Array indexes are zero-based
JavaScript arrays are written with square brackets [].

8) function :

#javascriptdatatypes

javascript datatypes