really really basic question

[robert_gsfame]

which one is correct  if(blablabla !=="")  or (blablabla !="") both in php and javascript

 

thx

[TeddyKiller]

Depends what you are wanting to do.

= means IS

== means EQUAL TO

=== means IDENTICAL TO

So.. if you are checking if something is NOT EQUAL TO something. You'd use !=

If you are checking if something is NOT IDENTICAL TO something. You'd use !==

[robert_gsfame]

what do u mean identical and equal, i really confused

this is not about mysql but javascript function and php

 

could u please explain a bit.....equal means everything that cope with number and identical for character??

[Ken2k7]

Read all about it here - http://www.php.net/manual/en/language.operators.comparison.php

 

Basically, 0 == false but 0 !== false because 0 and false are not the same type. 0 is an int. false is a boolean.

[robert_gsfame]

okay so anything that deals with string, !== must be used instead of != which should be used for numeric (integer)

[deanlearner]

the number 0 == false : returns true

the number 0 === false : returns false because the data types are different

the string '1' == true : returns true

the string '1' === true : returns false because the data types are different

[TeddyKiller]

what do u mean identical and equal, i really confused

this is not about mysql but javascript function and php

 

could u please explain a bit.....equal means everything that cope with number and identical for character??

Yes. What I mentioned works in PHP and most probably Javascript.

 

= - Assignment

== - Value equality

!= - Value inequality

=== - Type and value equality

!== - Type and value inequality

 

$date = '1';
//$date now contains the value of 1.
if($date == '1') {
//Checks if $date has the value of 1, and returns true.
if($date != '2') {
//Checks if $date does not have the value of two, and returns true.

Can't think of examples with === and !==

Though, what is explained above is all true. You'll probs be needing != in your statement

[Ken2k7]

okay so anything that deals with string, !== must be used instead of != which should be used for numeric (integer)

Nope, not necessarily. I'll use a real-life example with the function strpos.

 

strpos is a function that searches whether a substring of a string exists. If so, it returns the index at where the substring starts at. One possible return value is 0 (which means at the beginning of the string).

 

strpos("phpfreaks", "php");

The string php is at the start of phpfreaks so strpos returns the number 0.

 

However, if the substring is not found, strpos returns the boolean value false.

 

strpos("phpfreaks", "o");

o is not in phpfreaks, so it returns false.

 

Now, say you want to check if a substring is in a string. If you used == it won't work because 0 == false; however 0 !== false.

 

if (strpos("phpfreaks", "o") === false) // o is not in phpfreaks

 

Hope this helps.

[Adam]

Basically === checks they are of the same data type too.