if('00' == '0000') returns true

[programming.name]

 

<?php

if('00' == '000')

echo 'weired';

?>

 

 

Please consider the code above. Strangely it echoes the word "weired".

 

Also if('00' == '000000000000000') returns true and so forth.

 

What is really going on?

 

Thanks in advance

 

By the way the php version is 5.3.9 on wampserver 2.2

 

[spiderwell]

if nothing == nothing then its true!

 

if '000' === '000' if EXACTLY the same then true

 

its like when you have a 0 return for some function which can be seen as false and not 0

 

so you use 3 equals signs!

 

(i think i didnt explain very well but I hope you get the idea)

[requinix]

For some reason it was decided that if you're loosely comparing two numeric strings, PHP will compare them as numbers.

 

Comparison Operators

If you compare a number with a string or the comparison involves numerical strings, then each string is converted to a number and the comparison performed numerically. These rules also apply to the switch statement. The type conversion does not take place when the comparison is === or !== as this involves comparing the type as well as the value.

 

As random as spiderwell's comment is, he actually said the right answer: use a strict comparison instead.

[xyph]

Further reading:

 

http://www.greymass.com/php-basics-the-operators-part-1/

[spiderwell]

As random as spiderwell's comment is, he actually said the right answer:

 

keeping this for signature!

[ManiacDan]

Everyone (except requinix since he's read it three times already) should read this

[The Little Guy]

add a third equal sign

 

<?php 
if('00' === '000')
echo 'weired';
?>

 

That will not only match 0 against 0 but it must also be of the same type (int, string, bool, float, etc.) it won't convert a string zero to an int.