PHP

Definition and Usage: The `filectime()` function returns the last modification time of a specified file. This function checks both the daily modification history of the file and the inode modification status. The inode modification status refers to changes in permissions, ownership, user group, or other metadata. If successful, the function returns the last modification time of the file in Unix timestamp format; if unsuccessful, it returns `FALSE`.

Execute a database query: Delete database; <br/>?php // Assume database username: root, password: 123456, database name: RUNOOB; $con = mysqli_connect('localhost', 'root', '123456', 'RUNOOB...');

Usage method: 1. Introduce the mailbox integration php file https://wwa.lanzoui.com/iHt6Xuqu41g2. Use function: &lt;?php /*Sending email method *@param $to: receiver $title: title $content: email content *@return bool true: sent successfully false: sent...

Determine whether it is https/** * Determine whether it is https * @return bool Returns true if it is https; otherwise returns false */ function is_https() { if ( !empty($_SERVER['HTTPS']) &amp;&amp; strtolower($_SERVE…

`<?php define("PI", 3.1415926); // Define a constant $r=12;//定义圆半径 echo &quot;半径为12的单位的圆的面积&quot;.PI*($r*$r); // Calculate the area??>` In PHP, the `define()` function is commonly used to define constants; alternatively, `const` can be used...

Use the PHP QR Code library to generate QR codes: After downloading the library provided by the official website (via the link at the bottom), simply use the `phpqrcode.php` file to generate QR codes – however, your PHP environment must support GD2. The `phpqrcode.php` file provides a key `png()` method; the parameter `$text` specifies the text data to be encoded into the QR code; the parameter `$outfile...`

MySQLi database connection: `<?php define('DB_NAME', 'api_4s5_cn'); define('DB_USER', 'api_4s5_cn'); define('DB_PASSWORD', '4Eh6DEsLCT5HebjR'); define('DB_HOST', 'lo...');`

<?php /** * Curl Version * Usage: * $post_string = &quot;app=request&amp;version=beta&quot;; * request_by_curl('http://localhost/restServer.php', $post_st...

This article provides a practical analysis of the efficiency differences and appropriate use cases between the `switch` and `if–else` statements in PHP – shared here for your reference. The detailed analysis is as follows: Both of these PHP control structures are used to determine whether a value meets a specific condition and to execute different actions accordingly (whether the condition is met or not). Regardless of the programming language used, developers always need to consider the execution efficiency of their code. After reviewing various resources, it was found that the `switch` and `if–else` statements behave differently in various scenarios...

<?php $email = &quot;demo@example.com&quot;; if (filter_var($email, FILTER_VALIDATE_EMAIL)) {echo '" ". $email. " " is valid.';} else {echo...