Luckily, PHP comes to the rescue with the = operator, which, if you recall, means 'is identical to', which means $pos must be equal to false and of the same type as false (boolean). However, PHP considers 0 to be the same value as false, which means that our if statement cannot tell the difference between 'Substring not found' and 'Substring found at index 0' - quite a problem! This time the problem lies in the fact that 'This' is the first thing in $string, which means that strpos() will return 0. Is it another case sensitivity problem? Not quite. If you try executing that, you will find that it outputs 'Not found', despite 'This' quite clearly being in $string. If the substring sent in parameter two is not found in parameter one, strpos() will return false. You can specify whole words in parameter two, which will make strpos() return the first position of that word within the string, for example strpos($string, 'test') would return 19 - the index of the first letter in the matched word.

Remember that PHP considers the first letter of a string to be index 0, which means that the A strpos() found is actually the ninth character. That will return 8, because the first character in 'This is a strpos() test' that is a lowercase A is at index 8. It is easier to explain in code, so here goes: Strpos(), and its case-insensitive sibling stripos(), returns the index of the first occurrence of a substring within a string. Int stripos ( string haystack, string needle ) Int strpos ( string haystack, string needle )

Php strpos