Basic operations related to AJAX
AJAX development
AJAX is "Asynchronous Javascript And XML” (asynchronous JavaScript and XML) refers to a web development technology for creating interactive web applications.
AJAX = Asynchronous JavaScript and XML (a subset of Standard Universal Markup Language).
AJAX is a technology for creating fast, dynamic web pages.
By exchanging a small amount of data with the server in the background, AJAX can enable asynchronous updates of web pages. This means that parts of a web page can be updated without reloading the entire page.
Traditional web pages (not using AJAX) must reload the entire web page if the content needs to be updated.
AJAX application example
1. Prompt for user name in the registration interface
The effect is as shown in the figure:
The code is as follows:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script src="bootstrap/js/jquery-1.11.2.min.js"></script>
</head>
<body>
<input type="text" id="uid" />
<span id="test"></span>
</body>
<script>//Ajax//用户注册名提示
$("#uid").blur(function(){ //取用户名
var uid = $(this).val(); //去数据库看用户是否存在
$.ajax({ url:"yhmchuli.php", //处理页面
data:{u:uid}, //传递数据；前为名，后为值
type:"POST", //数据提交方式
dataType:"TEXT", //返回的数据类型
success:function(data){ //回调函数
if(data.trim()=="ok"){ //trim()去掉php文件前后空格
$("#test").text("该用户名可以使用!");
$("#test").css("color","green");
}else{
$("#test").text("用户名已存在!");
$("#test").css("color","red");
}
}
});
}
)
</script>
</html>php processing page
<?php
$uid = $_POST["u"];
require_once "./DBDA.class.php";
$db = new DBDA();
$sql = "select count(*) from users where uid='{$uid}'";
$arr = $db->query($sql,0);
if($arr[0][0]){//用户名存在
echo "no";
}else{
echo "ok";
}The above is the detailed content of Basic operations related to AJAX. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
PyCharm usage tutorial: guide you in detail to run the operation
Feb 26, 2024 pm 05:51 PM
PyCharm is a very popular Python integrated development environment (IDE). It provides a wealth of functions and tools to make Python development more efficient and convenient. This article will introduce you to the basic operation methods of PyCharm and provide specific code examples to help readers quickly get started and become proficient in operating the tool. 1. Download and install PyCharm First, we need to go to the PyCharm official website (https://www.jetbrains.com/pyc
What is sudo and why is it important?
Feb 21, 2024 pm 07:01 PM
sudo (superuser execution) is a key command in Linux and Unix systems that allows ordinary users to run specific commands with root privileges. The function of sudo is mainly reflected in the following aspects: Providing permission control: sudo achieves strict control over system resources and sensitive operations by authorizing users to temporarily obtain superuser permissions. Ordinary users can only obtain temporary privileges through sudo when needed, and do not need to log in as superuser all the time. Improved security: By using sudo, you can avoid using the root account during routine operations. Using the root account for all operations may lead to unexpected system damage, as any mistaken or careless operation will have full permissions. and
Linux Deploy operation steps and precautions
Mar 14, 2024 pm 03:03 PM
LinuxDeploy operating steps and precautions LinuxDeploy is a powerful tool that can help users quickly deploy various Linux distributions on Android devices, allowing users to experience a complete Linux system on their mobile devices. This article will introduce the operating steps and precautions of LinuxDeploy in detail, and provide specific code examples to help readers better use this tool. Operation steps: Install LinuxDeploy: First, install
What to do if you forget to press F2 for win10 boot password
Feb 28, 2024 am 08:31 AM
Presumably many users have several unused computers at home, and they have completely forgotten the power-on password because they have not been used for a long time, so they would like to know what to do if they forget the password? Then let’s take a look together. What to do if you forget to press F2 for win10 boot password? 1. Press the power button of the computer, and then press F2 when turning on the computer (different computer brands have different buttons to enter the BIOS). 2. In the bios interface, find the security option (the location may be different for different brands of computers). Usually in the settings menu at the top. 3. Then find the SupervisorPassword option and click it. 4. At this time, the user can see his password, and at the same time find the Enabled next to it and switch it to Dis.
Huawei Mate60 Pro screenshot operation steps sharing
Mar 23, 2024 am 11:15 AM
With the popularity of smartphones, the screenshot function has become one of the essential skills for daily use of mobile phones. As one of Huawei's flagship mobile phones, Huawei Mate60Pro's screenshot function has naturally attracted much attention from users. Today, we will share the screenshot operation steps of Huawei Mate60Pro mobile phone, so that everyone can take screenshots more conveniently. First of all, Huawei Mate60Pro mobile phone provides a variety of screenshot methods, and you can choose the method that suits you according to your personal habits. The following is a detailed introduction to several commonly used interceptions:
How to get variables from PHP method using Ajax?
Mar 09, 2024 pm 05:36 PM
Using Ajax to obtain variables from PHP methods is a common scenario in web development. Through Ajax, the page can be dynamically obtained without refreshing the data. In this article, we will introduce how to use Ajax to get variables from PHP methods, and provide specific code examples. First, we need to write a PHP file to handle the Ajax request and return the required variables. Here is sample code for a simple PHP file getData.php:
How to solve the problem of jQuery AJAX error 403?
Feb 23, 2024 pm 04:27 PM
How to solve the problem of jQueryAJAX error 403? When developing web applications, jQuery is often used to send asynchronous requests. However, sometimes you may encounter error code 403 when using jQueryAJAX, indicating that access is forbidden by the server. This is usually caused by server-side security settings, but there are ways to work around it. This article will introduce how to solve the problem of jQueryAJAX error 403 and provide specific code examples. 1. to make
PHP string manipulation: a practical way to effectively remove spaces
Mar 24, 2024 am 11:45 AM
PHP String Operation: A Practical Method to Effectively Remove Spaces In PHP development, you often encounter situations where you need to remove spaces from a string. Removing spaces can make the string cleaner and facilitate subsequent data processing and display. This article will introduce several effective and practical methods for removing spaces, and attach specific code examples. Method 1: Use the PHP built-in function trim(). The PHP built-in function trim() can remove spaces at both ends of the string (including spaces, tabs, newlines, etc.). It is very convenient and easy to use.
