What is the function in php to delete a specified string?

php function to delete the specified string: 1. str_replace() function, syntax "str_replace(specified string,"", original string)"; 2. preg_replace() function, search by regular expression Specify a string and replace it with a null character.

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

Method 1: str_replace() function

str_replace() function replaces some characters in a string (case sensitive).

str_replace(find,replace,string,count)

This function must follow the following rules:

• If the searched string is an array, then it will return an array.

• If the searched string is an array, then it will find and replace each element in the array.

• If an array needs to be searched and replaced at the same time, and the elements to be replaced are less than the number of found elements, the excess elements will be replaced with empty strings .

• If you search an array and replace only one string, the replacement string will work for all found values.

Example:

<?php
echo str_replace("world","","Hello world!");
?>

Output:

Hello !

Method 2: preg_replace() function

preg_replace function performs a regular expression search and replace.

Syntax

preg_replace ( mixed $pattern , mixed $replacement , mixed $subject [, int $limit = -1 [, int &$count ]] )

Search for the part of subject that matches pattern and replace it with replacement.

Parameter description:

• $pattern: The pattern to be searched, which can be a string or a string array.

• $replacement: String or array of strings used for replacement.

• $subject: The target string or string array to be searched and replaced.

• $limit: Optional, the maximum number of substitutions for each subject string per pattern. The default is -1 (no limit).

• $count: Optional, the number of times the replacement is performed.

Return value

• If subject is an array, preg_replace() returns an array, otherwise it returns a string.

If a match is found, the replaced subject is returned, otherwise the unchanged subject is returned. If an error occurs, NULL is returned.

Example:

<?php
$str = &#39;a123abc112233/php.cn/aaccdd321123abcd&#39;;
echo preg_replace("#abc#i", "", $str);
?>

Output:

a123112233/php.cn/aaccdd321123d

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