PHP5中文手册·Find position of first occurrence of a string -- 追寻梦想＞编程乐园＞PHP 编程

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.

Warning

本函数可能返回布尔值 FALSE，但也可能返回一个与 FALSE 等值的非布尔值，例如 0 或者 ""。请参阅布尔类型章节以获取更多信息。应使用 === 运算符来测试本函数的返回值。

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。


	PHP5中文手册 strpbrk strrchr Strings PHP Manual 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`. Warning 本函数可能返回布尔值 `FALSE`，但也可能返回一个与 `FALSE` 等值的非布尔值，例如 0 或者 ""。请参阅布尔类型章节以获取更多信息。应使用 === 运算符来测试本函数的返回值。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。参见 strrpos() stripos() strripos() strrchr() substr() stristr() strstr() strpbrk strrchr Strings PHP Manual

strpos

说明

参数

返回值

范例

注释

参见