Wicked Cool PHP

#36: Finding Substrings

PHP has several functions that find a substring in a string. Your choice depends on what you want to do with the result. Here are three basic substring functions:

• strpos() finds the position of the substring's first occurrence.

• strrpos() finds the position of the last occurrence of the substring. Use this function in conjunction with substr() to extract everything past that point in the string.

• strstr() returns everything after the first occurrence of the substring.

All three of these functions return False if the substring isn't present. Because both a position and a string can evaluate to False when used in a conditional, it's very important that you check the type of the return value, as shown in the following script:

<?php ...