Detailed explanation of the steps to use mb_strpos in PHP

This time I will bring you a detailed explanation of the steps to use mb_strpos in PHP. What are the precautions when using mb_strpos in PHP? Here are practical cases, let’s take a look.

mb_strpos

(PHP 4 >= 4.0.6, PHP 5, PHP 7)
mb_strpos — Find position of first occurrence of string in a string
mb_strpos — Finds the first occurrence of string in another string

Description

int mb_strpos ( 
  string $haystack , 
  string $needle [, 
  int $offset = 0 [, 
  string $encoding = mb_internal_encoding() ]] 
  )
//Finds position of the first occurrence of a string in a string.
// 查找 string 在一个 string 中首次出现的位置。
//Performs a multi-byte safe strpos() operation based on number of characters. The first character's position is 0, the second character position is 1, and so on.
// 基于字符数执行一个多字节安全的 strpos() 操作。 第一个字符的位置是 0，第二个字符的位置是 1，以此类推。

Parameters

haystack

• The string being checked.

• The string being checked.

needle

• The string to find in haystack. In contrast with strpos(), numeric values ​​are not applied as the ordinal value of a character.

• Look for this string in haystack. Unlike strpos(), numeric values ​​are not treated as character sequential values.

offset

• The search offset. If it is not specified, 0 is used. A negative offset counts from the end of the string.

• The offset of the search position. If this parameter is not provided, 0 will be used. Negative offsets will be counted from the end of the string.

encoding

• The encoding parameter is the character encoding. If it is omitted, the internal character encoding value will be used.

• encoding parameter is character encoding. If omitted, the internal character encoding is used.

Return Values

• Returns the numeric position of the first occurrence of needle in the haystack string. If needle is not found, it returns FALSE .

• Returns the value of the first occurrence of needle in the haystack of string. If needle is not found, it returns FALSE.

Example

<?php
/** * Created by PhpStorm.
 * User: zhangrongxiang
 * Date: 2018/2/2
 * Time: 下午11:16
 */
$str = "Hello World! Hello PHP";
$pos = mb_strpos( $str, "Hello", 0, mb_internal_encoding() );
echo $pos . PHP_EOL;//0
$pos = mb_strpos( $str, "Hello", 2, mb_internal_encoding() );
echo $pos . PHP_EOL;//13
function mb_str_replace( $haystack, $search, $replace, $offset = 0, $encoding = 'auto' ) {
  $len_sch = mb_strlen( $search, $encoding );
  $len_rep = mb_strlen( $replace, $encoding );
  
  while ( ( $offset = mb_strpos( $haystack, $search, $offset, $encoding ) ) !== false ) {
    $haystack = mb_substr( $haystack, 0, $offset, $encoding )
          . $replace
          . mb_substr( $haystack, $offset   $len_sch,
        $le = mb_strlen( $haystack ) - mb_strlen( $search )   mb_strlen( $replace ),
        $encoding );
    //echo $le.PHP_EOL;
    $offset = $offset   $len_rep;
    if ( $offset > mb_strlen( $haystack, $encoding ) ) {
      break;
    }
  }
  
  return $haystack;
}
$replace = mb_str_replace( "hello world !hello world !hello world !hello world !", "hello", "hi" );
echo $replace . PHP_EOL; //hi world !hi world !hi world !hi world !
//hi PHP !hi PHP !hi PHP !hi PHP !
echo mb_str_replace( $replace, "world", "PHP" ) . PHP_EOL;
echo mb_str_replace( $replace, " ", "-" ) . PHP_EOL;
//PHP是世界上最好的语言

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