PHP: Find and replace with regex

Question

I have a variable which contains email addresses.

Examples:

    $email[1]="email(at)test.com";
    $email[2]="email[at]test.com";
    $email[3]="email(a)test.com";
    $email[4]="email(alfa)test.com";
    $email[5]="email[a]test.com";

How can I to perform in PHP a regex find all between () and [] and replace with "@". so in the end it will be like this:

    $email[1]="email@test.com";
    $email[2]="email@test.com";
    $email[3]="email@test.com";
    $email[4]="email@test.com";
    $email[5]="email@test.com";

All i have at the moment is this ((([a-zA-Z]+))|([[a-zA-Z]+]))

Answer 1

Regex:

[(\[][a-z]+[)\]]

Replacement string:

@

DEMO

Example:

<?php
$string = 'email(alfa)test.com';
$pattern = '~[(\[][a-z]+[)\]]~';
$replacement = '@';
echo preg_replace($pattern, $replacement, $string);
?> //=> email@test.com

Answer 2

Use this:

$replaced = preg_replace('~[([][^])]+[\])]~', '@', $yourstring);

Explanation

• ~[([] matches an opening bracket or brace
• [^])]+ matches any chars that are not a closing bracket or brace
• [\])] matches a closing bracket or brace
• We replace with @