How to find and replace string in php

php implementation method of finding and replacing strings: 1. Use the "substr_replace()" function to replace part of the string with another string; 2. Use the "str_replace()" function to replace a string other characters in the string.

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PHP String Replacement

Used to replace the specified string from a string.

Relevant functions are as follows:

substr_replace(): Replace part of a string with another string

str_replace(): Use a string to replace a part of a string Other characters

substr_replace()

substr_replace() function is used to replace part of a string with another string and return a mixed type.

Syntax:

mix substr_replace ( mixed string, string replacement, int start [, int length] )

Parameter description is as follows:

Parameter Description

string The string to be processed

replacement The character to be inserted String

start The starting position of the string. The starting position is 0. If it is negative, it starts from the specified position at the end of the string.

length is optional. The length returned by the string. The default is until characters The end of the string, if it is negative, return from the end of the string

Example:

<?php
echo substr_replace(&#39;abcdef&#39;, &#39;###&#39;, 1);//输出 a###
echo substr_replace(&#39;abcdef&#39;, &#39;###&#39;, 1, 2);//输出 a###def
echo substr_replace(&#39;abcdef&#39;, &#39;###&#39;, -3, 2);//输出 abc###f
echo substr_replace(&#39;abcdef&#39;, &#39;###&#39;, 1, -2);//输出 a###ef 
?>

Hint

If start is a negative number and length is less than or equal to start, length is 0.

str_replace()

str_replace() function uses one string to replace other characters in the string and returns a mixed type.

Syntax:

mixed str_replace( mixed search, mixed replace, mixed string [, int &count] )

The parameter description is as follows:

Parameter Description

search The string to be found (replaced)

replace The string to replace search

string The string to process

count Optional, a variable that counts the replacement

Example:

<?php
echo str_replace("world","earth","Hello world!");//输出 Hello earth!
//替换多个，且第二个参数为空字符
echo str_replace("o","","Hello world!");//输出 Hell wrld! 
//使用数组
$arr = array("e", "o");
$arr2 = array("x", "y");
echo str_replace($arr, $arr2, "Hello World of PHP", $i);//输出 Hxlly Wyrld yf PHP 
echo $i;//输出4  
?>

Tip

The difference between this function and substr_replace() is that all those that meet the conditions are replaced.

This function is case-sensitive. For case-insensitive search and replace, use str_ireplace()

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