How to replace specified string with empty in php

Method: 1. Use str_ireplace(), syntax "str_ireplace(specified substring, '', original string)"; 2. Use substr_replace(), syntax "substr_replace(original string, '' , position to start replacement, length of replacement)".

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

In PHP, you can use str_ireplace() and The str_replace() function uses a new string to replace a specific string specified in the original string. str_replace is case-sensitive, while str_ireplace() is not case-sensitive.

1. Use the str_ireplace() function to replace the string with an empty string

The syntax of str_ireplace() is as follows:

mixed str_ireplace ( mixed $search , mixed $replace , mixed $subject [, int &$count ] )

This function returns a string or array. This string or array is the result of replacing all search in subject with replace (ignoring case). The parameter count represents the number of times to perform the replacement.

Example: Replace the string with an empty string

<?php
$str = &#39;hello,world,hello,world&#39;;
$replace = &#39;&#39;;
$search = &#39;hello&#39;;
echo str_ireplace($search, $replace, $str);
?>

Output:

,world,,world

2. Use substr_replace() The function replaces the string with an empty string

substr_replace() The syntax of the function is as follows:

mixed substr_replace ( mixed $string , mixed $replacement , mixed $start [, mixed $length ] )

substr_replace() The copy of the string string will be made by start and optional length Parameter-qualified substrings are replaced using replacement.

If start is a positive number, replacement will start from the start position of string. If start is negative, the replacement will start at the start position from the bottom of string.

If the length parameter is set and is a positive number, it represents the length of the replaced substring in string. If set to a negative number, it represents the number of characters from the end of the substring to be replaced from the end of string. If this parameter is not provided, the default is strlen(string) (the length of the string). Of course, if length is 0, then the function of this function is to insert replacement at the start position of string.

Example: Replace the string with empty

<?php
$str = &#39;hello world!&#39;;
$replace = &#39;&#39;;
echo substr_replace($str, $replace, 0,5);
?>

Output:

world!

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