Returns the numeric position of the first occurrence of
needle in the haystack
string. Unlike strpos(),
stripos() is case-insensitive.
Note that the needle may be a string of one or
more characters.
If needle is not found,
stripos() will return boolean FALSE.
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
beginning of haystack.
注意: 本函数可安全用于二进制对象。
See also strpos(), strrpos(), strrchr(), substr(), stristr(), strstr(), strripos() and str_ireplace().