stripos()

(PHP 5, PHP 7)

查找字符串首次出现的位置（不区分大小写）

说明

stripos(string $haystack, string $needle[,int $offset= 0] ): int

返回在字符串$haystack中$needle首次出现的数字位置。

与strpos()不同，stripos()不区分大小写。

参数

$haystack

在该字符串中查找。

$needle

注意$needle可以是一个单字符或者多字符的字符串。

如果$needle不是一个字符串，那么它将被转换为整型并被视为字符顺序值。

$offset

可选的$offset参数，从字符此数量的开始位置进行搜索。如果是负数，就从字符末尾此数量的字符数开始统计。

返回值

返回 needle 存在于$haystack字符串开始的位置(独立于偏移量)。同时注意字符串位置起始于 0，而不是 1。

如果未发现 needle 将返回FALSE。

Warning

此函数可能返回布尔值FALSE，但也可能返回等同于FALSE的非布尔值。请阅读布尔类型章节以获取更多信息。应使用===运算符来测试此函数的返回值。

更新日志

范例

Example #1stripos()范例

<?php
$findme    = 'a';
$mystring1 = 'xyz';
$mystring2 = 'ABC';
$pos1 = stripos($mystring1, $findme);
$pos2 = stripos($mystring2, $findme);
// 'a' 当然不在 'xyz' 中
if ($pos1 === false) {
    echo "The string '$findme' was not found in the string '$mystring1'";
}
// 注意这里使用的是 ===。简单的 == 不能像我们期望的那样工作，
// 因为 'a' 的位置是 0（第一个字符）。
if ($pos2 !== false) {
    echo "We found '$findme' in '$mystring2' at position $pos2";
}
?>

注释

Note:此函数可安全用于二进制对象。

参见

• mb_stripos()大小写不敏感地查找字符串在另一个字符串中首次出现的位置
• strpos()查找字符串首次出现的位置
• strrpos()计算指定字符串在目标字符串中最后一次出现的位置
• strripos()计算指定字符串在目标字符串中最后一次出现的位置（不区分大小写）
• stristr()strstr 函数的忽略大小写版本
• substr()返回字符串的子串
• str_ireplace()str_replace 的忽略大小写版本

I found myself needing to find the first position of multiple needles in one haystack. So I wrote this little function:
<?php
function multineedle_stripos($haystack, $needles, $offset=0) {
  foreach($needles as $needle) {
    $found[$needle] = stripos($haystack, $needle, $offset);
  }
  return $found;
}
// It works as such:
$haystack = "The quick brown fox jumps over the lazy dog.";
$needle = array("fox", "dog", ".", "duck")
var_dump(multineedle_stripos($haystack, $needle));
/* Output:
  array(3) {
   ["fox"]=>
   int(16)
   ["dog"]=>
   int(40)
   ["."]=>
   int(43)
   ["duck"]=>
   bool(false)
  }
*/
?>

Regarding the function by spam at wikicms dot org
It is very bad practice to use the same function name as an existing php function but have a different output format. Someone maintaining the code in the future is likely to be very confused by this. It will also be hard to eradicate from a codebase because the naming is identical so each use of stripos() would have to be analyzed to see how it is expecting the output format (bool or number/bool).
Calling it string_found() or something like that would make a lot more sense for long-term use.

Unlike strpos() it seems that stripos() does NOT issue a WARNING if the needle is an empty string ''.

Regarding the === note, it might be worth clarifying that the correct tests for a binary found/not found condition are !==false to detect found, and ===false to detect not found.

Finding numbers in strings requires you to cast the number to string first.
strpos("123", 2) !== strpos("123", "2")

A handy function if you need to adjust layout based on whether or not a string contains descending letters:
<?php function containsDescenders($text) {
  $descenders = array("g","j","p","q","y");
  foreach ($descenders as $letter) {
    if (stripos($text,$letter) !== false) {
      return true;
    }
  }
  return false;
} ?>

this would to work with any language, i hope.
tested on czech (eastern europe) lang.
<?php
/****************************************
*  SAFE HIGHLIGHT
****************************************/
/**
 * function finds and encase every string in a $needleArr array with
 * strings $shearLft (from the left side) and $shearRgt (guess from which
 * side).
 * already encased needles are IGNORED for any other step, so order
 * of needles in $needleArr is pretty important.
 * 
 * function is searching needles in case-insensitive mode,
 * but case in the subject is saved.
 * 
 * can you do it better? so, do it.
 *
 * @param array $needleArr array of needles
 * @param string $shearLft left shear
 * @param string $shearRgt right shear
 * @param string $subject subject
 * @param string $encoding encoding ('utf-8' is default)
 * 
 * @author griffin
 */
function safeHighlight( $needleArr, $shearLft, $shearRgt, $subject, $encoding = 'utf-8')
{
  
  // encoding
  $e = $encoding;
  
  // oh, no needles
  if( !is_array( $needleArr))
    return $subject;
    
  // empty keys throw-off, only unique, reindex
  $nA = array_values(
      array_unique(
        array_diff( $needleArr, array(''))
      )
    );
  
  // needle count
  if( !($nC = count( $nA)))
    return $subject; // nothing to hl
    
  // shear length
  if( !(($rLL = mb_strlen( $rL = $shearLft, $e))
  + ($rRL = mb_strlen( $rR = $shearRgt, $e))))
    return $subject; // no shears
  
  // subject length
  if( !($sL = mb_strlen( $s = $subject, $e)))
    return null; // empty subject
    
  // subject in lowercase (we need to aviod
  // using mb_stripos due to PHP version)
  $sW = mb_strtolower( $s, $e);
  
  // masking ~ 0=not changed, 1=changed
  $m = str_repeat( '0', $sL);
  
  // loop for each needle
  for( $n=0; $n<$nC; $n++)
  {
    
    // needle string loWercase
    $nW = mb_strtolower( $nA[ $n], $e);
    
    $o = 0; // offset
    $nL = mb_strlen( $nW, $e); // needle length
    // search needle
    while( false !== ($p = mb_strpos( $sW, $nW, $o, $e)))
    {
      // oh hurrey, needle found on $p position
      
      // is founded needle already modified? (in full-length)
      for( $q=$p; $q<($p+$nL); $q++)
        if( $m[ $q])
        {
          // ai, caramba. already modified, jump over
          $o+= $nL;
          
          // continue for while() loop - not for for() loop!
          continue 2;
        }
      
      // explode subject and mask into three parts
      // partA | needle | partB
      $sE[0] = mb_substr( $s, 0, $p, $e);
      $sE[1] = mb_substr( $s, $p, $nL, $e);
      $sE[2] = mb_substr( $s, $p+$nL, $sL-$p-$nL, $e);
      
      // mask
      // partA | partB (needle not needed)
      $mE[0] = mb_substr( $m, 0, $p, $e);
      $mE[1] = mb_substr( $m, $p+$nL, $sL-$p-$nL, $e);
      
      // apply shears
      $sE[1] = $rL.$sE[1].$rR;
      
      // update sunject length
      $sL+= $rLL + $rRL;
      
      // update mask
      $m = $mE[0] . str_repeat( '1', $rLL + $nL + $rRL) . $mE[1];
      
      // implode into a subject
      $s = implode( $sE);
      
      // update lowercase subject
      $sW = mb_strtolower( $s, $e);
      
      // increase offset
      $o+= $rLL + $nL + $rRL;
      
      // end of string reached
      if( $o>=$sL)
        break;
      
    } // while()
    
  } // for( $n=0; $n<$nC; $n++)
  
  // oouu yeaaa, kick the subject out of the function
  return $s;
  
} // function safeHighlight()
/****************************************
*  END: SAFE HIGHLIGHT
****************************************/
?>

If you like using ternary operator, I wrote simple example how to use stripos function.
Also, in my example I add "How to use namespaces" for wide knowledges for newbies.
<?php
namespace My;
//You can be free using core functions in your NameSpaces (My)
function stripos($haystack, $needle) {
  //To call core function (from global NS) you should add backslash only - \func
  return (FALSE === \stripos($haystack, $needle)) ? FALSE : TRUE;
}
var_dump(stripos($haystack = 'John knows English language.', $needle = 'john')); //TRUE
var_dump(stripos($haystack = 'Sara knows English language too.', $needle = 'john')); //FALSE
?>