stristr

(PHP 4, PHP 5, PHP 7, PHP 8)

stristr — strstr() 函数的忽略大小写版本

说明

stristr(string $haystack, string $needle, bool $before_needle = false): string|false

返回 haystack 字符串从 needle 第一次出现的位置开始到结尾的字符串。

参数

haystack

在该字符串中查找。

needle

要搜索的字符串。

Prior to PHP 8.0.0, if needle is not a string, it is converted to an integer and applied as the ordinal value of a character. This behavior is deprecated as of PHP 7.3.0, and relying on it is highly discouraged. Depending on the intended behavior, the needle should either be explicitly cast to string, or an explicit call to chr() should be performed.

before_needle

若为 true，strstr() 将返回 needle 在 haystack 中的位置之前的部分(不包括 needle)。

参数 needle 和 haystack 将以不区分大小写的方式对待。

返回值

返回匹配的子字符串。如果 needle 未找到，返回 false。

更新日志

版本	说明
8.2.0	大小写转换不在依赖于使用 setlocale() 设置的区域。只会进行 ASCII 大小写转换。非 ASCII 字节值将通过它们的字节值进行比较。
8.0.0	`needle` 现在接受空字符串。
8.0.0	不再支持 int 传递给 `needle`。
7.3.0	弃用 int 传递给 `needle`。

示例

示例 #1 stristr() 示例

<?php
  $email = 'USER@EXAMPLE.com';
  echo stristr($email, 'e'); // 输出 ER@EXAMPLE.com
  echo stristr($email, 'e', true); // 输出 US
?>

示例 #2 测试字符串的存在与否

<?php
  $string = 'Hello World!';
  if(stristr($string, 'earth') === FALSE) {
    echo '"earth" not found in string';
  }
// 输出: "earth" not found in string
?>

示例 #3 使用非字符串 needle

<?php
  $string = 'APPLE';
  echo stristr($string, 97); // 97 = 小写字母 a
// 输出: APPLE
?>

注释

注意: 此函数可安全用于二进制对象。

参见

strstr() - 查找字符串的首次出现
strrchr() - 查找指定字符在字符串中的最后一次出现
stripos() - 查找字符串首次出现的位置（不区分大小写）
strpbrk() - 在字符串中查找一组字符的任何一个字符
preg_match() - 执行匹配正则表达式

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＋添加备注

用户贡献的备注 5 notes

down

dpatton.at.confluence.org ¶

22 years ago

There was a change in PHP 4.2.3 that can cause a warning message
to be generated when using stristr(), even though no message was
generated in older versions of PHP.

The following will generate a warning message in 4.0.6 and 4.2.3:
  stristr("haystack", "");
     OR
  $needle = "";  stristr("haystack", $needle);

This will _not_ generate an "Empty Delimiter" warning message in
4.0.6, but _will_ in 4.2.3:
  unset($needle); stristr("haystack", $needle);

Here's a URL that documents what was changed:
http://groups.google.ca/groups?selm=cvshholzgra1031224321%40cvsserver

down

giz at gbdesign dot net ¶

17 years ago

Just been caught out by stristr trying to converting the needle from an Int to an ASCII value.



Got round this by casting the value to a string.



<?php

if( !stristr( $file, (string) $myCustomer->getCustomerID()  ) ) {

  // Permission denied

}

?>

down

Techdeck at Techdeck dot org ¶

22 years ago

An example for the stristr() function:

<?php
$a = "I like php";
if (stristr("$a", "LikE PhP")) {
print ("According to \$a, you like PHP.");
}
?>

It will look in $a for "like php" (NOT case sensetive. though, strstr() is case-sensetive).

For the ones of you who uses linux.. It is similiar to the "grep" command.
Actually.. "grep -i".

down

-1

notepad at codewalkers dot com ¶

19 years ago

<?php



function stristr_reverse($haystack, $needle) {

  $pos = stripos($haystack, $needle) + strlen($needle);

  return substr($haystack, 0, $pos);

}

$email = 'USER@EXAMPLE.com';

echo stristr_reverse($email, 'er');

// outputs USER



?>

down

-3

jukka ¶

10 years ago

I think there is a bug in php 5.3 in stristr with uppercase Ä containing other character

http://pastebin.com/5bP6uztY

if you search only with täry it works, but as soon as the word is tärylä  it does not. TÄRYL works fine