How to use strpos to determine if a string exists in input string?

Question

$filename = 'my_upgrade(1).zip'; $match = 'my_upgrade';  if(!strpos($filename, $match))     {     die();     } else     {    //proceed    } 

In the code above, I'm trying to die out of the script when the filename does not contain the text string "my_upgrade". However, in the example given, it should not die since "my_upgrade(1).zip" contains the string "my_upgrade".

What am I missing?

Answer 1

strpos returns false if the string is not found, and 0 if it is found at the beginning. Use the identity operator to distinguish the two:

if (strpos($filename, $match) === false) { 

By the way, this fact is documented with a red background and an exclamation mark in the official documentation.

Answer 2

The strpos() function is case-sensitive.

if(strpos($filename, $match) !== false)         {         // $match is present in $filename         }     else         {        // $match is not present in $filename         } 

For using case-insensitive. use stripos() that is it finds the position of the first occurrence of a string inside another string (case-insensitive)