PHP：查找并替换正则表达式

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]="[e-mail]";
    $email[2]="[e-mail]";
    $email[3]="[e-mail]";
    $email[4]="[e-mail]";
    $email[5]="[e-mail]";

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);
?> //=> [e-mail]