Returns the numeric position of the first occurrence of needle in the haystack string. Unlike the strrpos(), this function can take a full string as the needle parameter and the entire string will be used.
If needle is not found, returns false.
Note: It is easy to mistake the return values for "character found at position 0" and "character not found". Here's how to detect the difference:
If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
The optional offset parameter allows you to specify which character in haystack to start searching. The position returned is still relative to the the beginning of haystack.
See also strrpos(), strrchr(), substr(), stristr(), and strstr().