stristr

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

stristrstrstr() 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 truestrstr() 将返回 needlehaystack 中的位置之前的部分(不包括 needle)。

参数 needlehaystack 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

add a note add a note

User Contributed Notes 8 notes

up
13
dpatton.at.confluence.org
21 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
up
6
giz at gbdesign dot net
16 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
}
?>
up
2
Techdeck at Techdeck dot org
21 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".
up
-3
notepad at codewalkers dot com
18 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

?>
up
-7
jukka
9 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
up
-8
art at awilton dot dotcom
18 years ago
handy little bit of code I wrote to take arguments from the command line and parse them for use in my apps.

<?php

$i
= implode(" ",$argv); //implode all the settings sent via clie
$e = explode("-",$i); // no lets explode it using our defined seperator '-'

       //now lets parse the array and return the parameter name and its setting
       // since the input is being sent by the user via the command line
       //we will use stristr since we don't care about case sensitivity and
       //will convert them as needed later.

   
while (list($index,$value) = each($e)){

      
//lets grap the parameter name first using a double reverse string
       // to get the begining of the string in the array then reverse it again
       // to set it back. we will also "trim" off the "=" sign

    
$param = rtrim(strrev(stristr(strrev($value),'=')),"=");

      
//now lets get what the parameter is set to.
       // again "trimming" off the = sign

    
$setting = ltrim(stristr($value,'='),"=");

      
// now do something with our results.
       // let's just echo them out so we can see that everything is working

     
echo "Array index is ".$index." and value is ".$value."\r\n";
      echo
"Parameter is ".$param." and is set to ".$setting."\r\n\r\n";

}

?>

when run from the CLI this script returns the following.

[root@fedora4 ~]# php a.php -val1=one -val2=two -val3=three

Array index is 0 and value is a.php
Parameter is  and is set to

Array index is 1 and value is val1=one
Parameter is val1 and is set to one

Array index is 2 and value is val2=two
Parameter is val2 and is set to two

Array index is 3 and value is val3=three
Parameter is val3 and is set to three

[root@fedora4 ~]#
up
-14
greg at no_ggmac_reply dot com
13 years ago
Beware the example given here:

if stristr($message,'viagra')
or stristr($message,'cialis')
)
{
die();
}

stristr does not search for words, it finds matching substrings.  So, for example, the check for 'cialis' will trigger on 'specialist'
up
-14
tomas dot nesrovnal at yourspirit dot cz
15 years ago
Active item item in menu:

<?php
function aim($page) {
    if(
stristr($_SERVER['REQUEST_URI'], $page)) {
        return
' class="active"';
    }
}
?>

usage:

<style type="text/css">
.active {color: red;}
</style>

<?php
print '<a href="http://example.com/page/hello-world/"'. aim('hello-world') .'>HW</a>';
?>
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