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Javascript Operators === & !==

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4.33/5 (6 votes)
28 Feb 2011CPOL 20.2K   5   6
Javascript Operators === & !==
The following example will demonstrate the Tip:
var x;
x = 0;
var y;
y = '0';

x is numeric, while y is char.

On comparing them using the "==" operator, it will give true !
alert('x == y : ' + (x==y));


To do so, we will use the '===' operator:
alert('x === y : ' + (x===y));

which checks on the Value and Type, so it will give false.

Same for the !== operator.
alert('x != y: '; + (x != y));

it gives false !!
alert('x !== y: '; + (x !== y));

it gives true


So, to assure an accurate comparison datatype and value don't use the normal operators == and != but use === and !== operators.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer
Egypt Egypt
- BSc Computer Engineering
Ain Shams University - Faculty of Engineering

Comments and Discussions

 
GeneralReason for my vote of 4 I like the tip because before knowin... Pin
Jagz W11-Mar-11 4:46
professionalJagz W11-Mar-11 4:46 
GeneralReason for my vote of 4 it is a good tip, and important for ... Pin
egozi1310-Mar-11 9:30
egozi1310-Mar-11 9:30 
GeneralReason for my vote of 5 nice tip. Pin
pankajupadhyay291-Mar-11 7:39
professionalpankajupadhyay291-Mar-11 7:39 
GeneralReason for my vote of 3 Nice tip to take care while using sc... Pin
r verma23-Feb-11 16:49
r verma23-Feb-11 16:49 
GeneralReason for my vote of 3 Nice tip to take care while using sc... Pin
r verma23-Feb-11 16:46
r verma23-Feb-11 16:46 
GeneralOperator Use == returns true if values o... Pin
r verma23-Feb-11 16:43
r verma23-Feb-11 16:43 
Operator Use
== returns true if values of variables are equal
=== returns true if values and variable types are same
!= true if values are not equal
!=== true if values and variable types are not same

These are operators provided in Javascript for comparison. Nice tip to take care while using script.

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