An interesting bug !!

[prathyush]

Why does the second return success do you think?

 

$txnResponseCode = "E";

 

if ($txnResponseCode != "0") {

 

echo 'fail<br>';

 

 

} else {

 

echo 'success<br>';

 

}

 

if ($txnResponseCode != 0) {

 

echo 'fail<br>';

 

 

} else {

 

echo 'success<br>';

 

}

[mattal999]

Because in the second you are testing for an integer, when the variable you should be testing for is a string. This will result in unexpected behaviour.

 

And btw, it returns Success because the string 'E' does not equal 0.

[ignace]

This isn't a bug. For more information: http://us2.php.net/manual/en/types.comparisons.php

[GingerRobot]

The reason for this behavior is because, as the manual page says:

 

If you compare an integer with a string, the string is converted to a number. If you compare two numerical strings, they are compared as integers. These rules also apply to the switch statement.

 

If you cast 'E' as an integer, it is 0.

 

Edit: Holdup. I think i read this wrong.

Edit again: No, i didn't.

[ignace]

If you cast 'E' as an integer, it is 0.

 

Don't he cast E to ord(E)=69 and use that to compare it to 0? $txnResponseCode != 0 thus 69 != 0 => true. So to what does he cast the entire if statement?

 

it returns Success because the string 'E' does not equal 0.

 

if ($txnResponseCode != 0) { // E does not equal 0 => true
echo 'fail<br>';
}

 

Edit: my first reply was to fast without proper thinking it through

[GingerRobot]

Don't he cast E to ord(E)=69 and use that to compare it to 0? $txnResponseCode != 0 thus 69 != 0 => true

 

No.

 

This code:

 

$var = (int) "E";
var_dump($var);
$var = (float) "E";
var_dump($var);

 

Produces:

 

int(0)

float(0)

 

The reason I cast it to both an integer and a float is because the string contains the character 'E'. Any strings containing e, E, or '.' are converted to a float prior to comparison with a numeric value. See this page: http://us2.php.net/manual/en/language.types.string.php#language.types.string.conversion

[ignace]

Do not expect to get the code of one character by converting it to integer, as is done in C -- http://us2.php.net/manual/en/language.types.string.php#language.types.string.conversion

 

Didn't knew their were differences between languages thought they all used the same mechanism.. Thank you Ginger for pointing this out.

[d.shankar]

lol , the topic starter hasn't even replied... but the discussion goes on

 

phpfreaks rocks !

[ignace]

lol , the topic starter hasn't even replied... but the discussion goes on

 

phpfreaks rocks !

 

We get to the bottom of it

[d.shankar]

thats true..