How to use and the difference between post and get methods in ajax

This article will introduce the get and post requests in ajax, which has certain reference value. I hope it will be helpful to everyone learning ajax

Ajax meaning

AJAX stands for "Asynchronous Javascript And XML" (Asynchronous JavaScript and XML), which refers to a web development technology for creating interactive web applications. AJAX is actually asynchronous JavaScript and XML. It is a technology used to create fast and dynamic web pages. It can also make web pages update asynchronously by exchanging a small amount of data with the server in the background. The application of this technology means that a certain part of the web page can be updated without reloading the entire web page. [ajax tutorial]

There are two important concepts in ajax, which are the knowledge of get and post. Today I will introduce to you how to use these two knowledge points and the relationship between them. Difference

GET() request

get() method loads information through remote http get request. When the request is successful, the callback function can be called

Parameters The parameters are passed through the ? in the URL address, so that the data is passed to the server

格式：
 get(URL,callback);
 URL ：传递想传递的url,必需具备
 callback：参数是请求成功后所执行的函数名，可选

For example

var xhr = new XMLHttpRequest()
xhr.open('GET', './demo.php?id=1)//open 方法的第一个参数的作用就是设置请求的方法
xhr.send(null)// 需要提交到服务端的数据可以通过 send 方法的参数传递
xhr.onreadystatechange = function () {
  if (this.readyState === 4) {
    console.log(this.responseText)
  }
}

POST request

In the process of requesting data from the server through http post request, the request body must be used to carry the data that needs to be submitted

格式：
post(url,data,success(data, textStatus, jqXHR),dataType)
url ：规定把请求发送到哪个 URL。必须具备
data：映射或字符串值,指请求发送到服务器的数据，是可选的   
success(data, textStatus, jqXHR）：指请求成功时执行的回调函数，可选的    
dataType：服务器响应的数据类型

例如
var xhr = new XMLHttpRequest()
xhr.open('POST', './add.php')
// 设置请求头中的 Content‐Type 为 application/x‐www‐form‐urlencoded以便于服务端接收数据
xhr.setRequestHeader('Content‐Type', 'application/x‐www‐form‐urlencoded')
xhr.send('key1=value1&key2=value2')
xhr.onreadystatechange = function () {
  if (this.readyState === 4) {
    console.log(this.responseText)
    }
    }

The difference between post and get

get It is to obtain data from the server, while post is to submit data to the server. Under normal circumstances, get passes data of a parameter nature, while post is all business data.

Use post when sending a large amount of data, and send a small amount of data. Use get

to summarize: The above is the content of this article. Through this article, I hope everyone has a certain understanding of the get and post methods

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