How to query the last occurrence of a string in php

Two methods to query the last occurrence position: 1. Use the strripos() function query, which can calculate and return the last occurrence position of the specified string in the target string in a case-insensitive manner. The syntax is " strripos (string being searched, string to be found, position to start searching)". 2. Use the strrpos() function to query, which can perform case-sensitive calculations and return the position of the last occurrence. The syntax is "strrpos (string being searched, string to be found, position to start searching)".

The operating environment of this tutorial: windows7 system, PHP version 8.1, DELL G3 computer

How to query the last occurrence of a string in php ? PHP has two built-in functions to achieve this function:

• strripos(): Find the last occurrence of a string in another string (case insensitive).

• strrpos(): Find the last occurrence of a string in another string (case sensitive).

1. Case-insensitive query using strripos() function

strripos() is used to calculate the position of the specified string in the target string The position of the last occurrence in (not case sensitive).

The syntax is as follows:

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

The parameter description is as follows:

• haystack: Search in this string.

• needle: needle can be a single character or multi-character string. If needle is not a string, it is converted to an integer and treated as a character-order value.

• offset: The optional offset parameter allows you to specify which character in the haystack to start searching from. The returned position numeric value is still relative to the starting position of the haystack.

  A negative offset will cause the search to start from the beginning of the string and end at the offset position.

Returns the position where the needle exists (independent of the offset) of the last occurrence of the haystack string. Also note that the string position starts at 0, not 1. If needle is not found, false will be returned.

Implementation example:

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);  
$findme = &#39;c&#39;;
$findme1 = &#39;C&#39;;
$mystring = &#39;ABCabcabcABC&#39;;
$pos1 = strripos($mystring, $findme);
$pos2 = strripos($mystring, $findme1);
var_dump($mystring);
var_dump($pos1);
var_dump($pos2);
?>

2. Case-sensitive query using strrpos() function

strrpos () is used to calculate the position of the last occurrence of the specified string in the target string.

The syntax is as follows:

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

• The parameters of the strrpos() function and strripos( ) is similar and can be referred to.

If the offset is a negative number, it will cause the search to end at the count position starting from the end of the string.

Implementation code:

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);  
$findme = &#39;c&#39;;
$findme1 = &#39;C&#39;;
$mystring = &#39;ABCabcabcABC&#39;;
$pos1 = strrpos($mystring, $findme);
$pos2 = strrpos($mystring, $findme1);
$pos3 = strrpos($mystring, $findme1,-5);

var_dump($mystring);
var_dump($pos1);

var_dump($mystring);
var_dump($pos2);

var_dump($mystring);
var_dump($pos3);
?>

Recommended learning: "PHP Video Tutorial"

The above is the detailed content of How to query the last occurrence of a string in php. For more information, please follow other related articles on the PHP Chinese website!