strpos
(PHP 4, PHP 5)
strpos — Find position of first occurrence of a string
说明
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() before PHP 5, this function can take a full string as the needle parameter and the entire string will be used.
参数
- haystack
-
- needle
-
If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
- offset
-
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 .
返回值
Returns the position as an integer. If needle is not found, strpos() will return boolean FALSE.
范例
Example#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
?>
注释
Note: 本函数可安全用于二进制对象。