strpos

Description

int strpos ( string haystack, mixed needle [, int offset] )

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, strpos() will return boolean FALSE.

警示

本函數可能返回布林值 FALSE，但也可能返回一個與 FALSE 等值的非布林值，例如 0 或是 ""。請參閱布爾類型章節以取得更多訊息。應使用 === 運算符來測試本函數的返回值。

注: 本函數可安全用於二進位對象。

例子 1. strpos() examples
<?php $mystring = 'abc'; $findme = 'a'; $pos = strpos($mystring, $findme); // Note our use of ===. Simply == would not work as expected // because the position of 'a' was the 0th (first) character. if ($pos === false) { echo "The string '$findme' was not found in the string '$mystring'"; } else { echo "The string '$findme' was found in the string '$mystring'"; echo " and exists at position $pos"; } // We can search for the character, ignoring anything before the offset $newstring = 'abcdef abcdef'; $pos = strpos($newstring, 'a', 1); // $pos = 7, not 0 ?>

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.