what is the difference between '!= 'and '!== '

Question

Possible Duplicates:
Is there a difference between !== and != in PHP?
Javascript === vs == : Does it matter which “equal” operator I use?

In some cases when checking for not equal, I saw using != and in some places i saw !==. Is there any difference in that?

Example:

var x = 10;   

if (x != 10) {   
    //...
}

and

if (x !== 10) {    
    //...
}

score 7 · Accepted Answer · answered Jul 02 '11 at 20:12

7

== compares only the value and converts between types to find an equality, === compares the types as well.

answered Jul 02 '11 at 20:12

Femaref

score 3 · Answer 2 · answered Jul 02 '11 at 20:12

3

1 is equal to "1", but not identical, because 1 is an integer and "1" is a string.

answered Jul 02 '11 at 20:12

rid

score 3 · Answer 3 · answered Jul 02 '11 at 20:12

3

They are different in terms of strictness of comparison. !== compares variable types in addition to values.

answered Jul 02 '11 at 20:12

Emre Yazici

score 2 · Answer 4 · answered Jul 02 '11 at 20:12

2

!== will also check the type (int, string, etc.) while != doesn't.

answered Jul 02 '11 at 20:12

score 2 · Answer 5 · edited May 23 '17 at 12:19

2

edited May 23 '17 at 12:19

Community

answered Jul 02 '11 at 20:13

Mark PM

score 2 · Answer 6 · answered Jul 02 '11 at 20:15

2

The difference is that == (and !=) compare only the value, === (and !==) compare the value and the type.

For example
"1" == 1 returns true
"1" === 1 returns false, because one is a string and the other is an integer

Hope this helps. Cheers

answered Jul 02 '11 at 20:15

6 Answers6