正则表达式'/^\w+$/i'中的 i 什么意思

Question

<?php

$user = array(

    'name' => 'spark1985',

    'email' => '[e-mail]',

    'mobile' => '13312345678'

);

if (!preg_match('/^\w+$/i', $user['name'])) {

    die('用户名不合法');

?>

Answer 1

就是不区分大小写是吧

Answer 2

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