Women in Technology

Hear us Roar


Article:
  Working with Files in PHP, Part 3
Subject:   line !== 'false'
Date:   2003-03-12 16:39:03
From:   johncogg
Response to: line !== 'false'

Although this behavior may work (not using the 'identical' comparison and just using a standard comparison) it is not to be relied on. For instance:


$myfile = "0"; // a filename whose name is '0'
if($myfile == false) {
echo "$myfile is false\n";
} else {
echo "$myfile is true.\n";
}


In this case, the string '0' will be evaluated as an integer value '0' which is in turn a boolean false. In order for this to behave properly you'd need to use the identical comparison === operator.


John
Full Threads Oldest First

Showing messages 1 through 1 of 1.

  • line !== 'false'
    2005-03-17 10:11:01  Cerro [View]

    I was looking for some code to list the directory content with PHP3. The problem that i had was that i had a subdirectory named 0. Since in PHP3 there is no !== operator i did like this:

    function ListDir($dir)
    {
    if ((file_exists($dir)) && ($dh = opendir($dir)))
    {
    while (($file = readdir($dh)) || (((string) $file == "0") || ($file != false)))
    echo($file);
    closedir($dh);
    }
    }

    In this case the problem directory name is "0" but you can add "false" to the condition.



Recommended for You
 
Sign up today to receive special discounts,
product alerts, and news from O'Reilly.
Privacy Policy >
View Sample Newsletter >