About the differences and use of $.get (), $.post (), $.ajax () in jquery

　　

First, these three methods are the type of request that the Ajax method requires to exchange data with the server.

First, $.get ()

The $.get () method loads data from the server using an HTTP GET request.

Usage format: $.get (Url,[data],[callback])

Description: URL is the request address,

Data is the list of requests ( optional ), and the parameters to be passed are written in the URL .

Callback is the callback function after the successful request, the function accepts two parameters, the first is the data returned by the server, the second parameter is the state of the server, is an optional parameter .

(where the format of the server return data is actually a string situation, not the JSON data format we want, this reference is just for comparison purposes.) ）

1 $ ("button"). Click (function() {2 $.get ("url",function(data, Status) {3 alert ("Data:" + Data + "Nstatus:" + status); 4 }); 5 　　

Official syntax: $.get (url,data,function(DATA,STATUS,XHR), DataType)

Parameters	Description
Url	Necessary. Specify the URL that you want to request.
Data	Optional. Specifies the data that is sent to the server along with the request.
function (DATA,STATUS,XHR)	Optional. Specifies the function to run when the request succeeds. Additional parameters: Data-contains results from the request Status-contains the requested State ("Success", "Notmodified", "Error", "Timeout", "ParserError") xhr -Contains XMLHttpRequest objects
DataType	Optional. Specifies the data type of the expected server response. By default, JQuery will be smart to judge. Possible types: "XML"-an XML document "HTML"-HTML as plain text "Text"-Plain text string "Script"-Runs the response in JavaScript and returns it as plain text "JSON"-runs the response in JSON and returns it as a JavaScript object "Jsonp"-load a JSON block with Jsonp and add a "? callback=?" To the URL to specify the callback

Second, $.post ()

The $.post () method loads data from the server using an HTTP POST request.

Official syntax:   $ (selector). Post (Url,data, function (DATA,STATUS,XHR), dataType)  

parameters	description
url	required. Specifies which URL to send the request to.
data	Optional. Specifies the data that is sent to the server along with the request.
function (data,status,xhr)	Optional. Specifies the function to run when the request succeeds. Additional parameters: Data -contains result data from the request status -contains the status of the request ("Success", "notmodified", "Error", "Timeout", "ParserError") xhr -Include XMLHttpRequest object
Em>datatype	Optional. Specifies the data type of the expected server response. By default, JQuery will be smart to judge. Possible types: "xml"-an XML document "HTML"-HTML as Plain text "text"-Plain text string "s Cript "-Runs the response in JavaScript and returns " JSON "in plain text-runs the response in JSON and returns " Jsonp "with a JavaScript object-loaded with JSONP A JSON block that will add a "? callback=?" To the URL to specify the callback

This function is similar to the $.get () parameter, has a type parameter, type is the data type returned , can be Html,xml,json, etc. If we set this parameter to: JSON, then the returned format is in JSON format, and if it is not set, it is the same as the format returned by $.get (), which is a string.

$.post ("Emp.do?p=getallemp", {id:deptid,x:math.random ()},function(data) {            var arry = eval ("(" +data+ ")"); // go to quotation marks, programming JSON string to the JSON type array, or you can add a parameter "JSON" after the $.post function to specify that the data received is a JSON-type             for (var i=0;i<arry.length;i++) {                varnew  Option (Arry[i].empname, ARRY[I].EMPID);                document.getElementById ("emp"). Options.add (OP);            }        });

SAN, $.ajax (Opiton)

　　Compared to the above two, this can perform precise demand control.

The Ajax () method is used to perform Ajax (asynchronous HTTP) requests.

All JQuery Ajax methods use the Ajax () method. This method is typically used for requests that other methods cannot complete .

Official syntax: $.ajax ({name:value, Name:value, ...})

the list of parameters that may appear in parentheses is as follows: (more important and common already marked red)

name	Value/Description
Async	A Boolean value that indicates whether the request is processed asynchronously. The default is true.
Beforesend (xhr)	The function that is run before the request is sent.
Cache	A Boolean value that indicates whether the browser caches the requested page. The default is true.
Complete (xhr,status)	A function that runs when the request completes (called after the request succeeds or fails, that is, after the success and the error function).
ContentType	The type of content to use when sending data to the server. The default is: "Application/x-www-form-urlencoded".
Context	Specifies the "This" value for all AJAX-related callback functions.
Data	Specifies the data to be sent to the server.
Datafilter (data,type)	A function for handling XMLHttpRequest raw response data.
DataType	The data type of the expected server response.
Error (xhr,status,error)	The function to run if the request fails.
Global	A Boolean value that specifies whether the global AJAX event handler is triggered for the request. The default is true.
Ifmodified	Boolean value that specifies whether the request succeeds only if the response has changed since the last request. The default is False.
Jsonp	A string that overrides the callback function in a JSONP.
Jsonpcallback	Specifies the name of the callback function in a JSONP.
Password	Specifies the password that is used in HTTP access authentication requests.
ProcessData	A Boolean value that specifies whether the data sent through the request is converted to a query string. The default is true.
Scriptcharset	Specifies the requested character set.
Success (result,status,xhr)	The function that is run when the request succeeds.
Timeout	Sets the local request time-out (in milliseconds).
Traditional	A Boolean value that specifies whether to use the traditional style of parameter serialization.
Type	Specifies the type of request (GET or POST).
Url	Specifies the URL to send the request to. The default is the current page.
Username	Specifies the user name to use in HTTP access authentication requests.
Xhr	The function used to create the XMLHttpRequest object.

Example:

1 //querying data by ID2 $.ajax ({3Type: "POST",//Request Type4URL: "Your URL address", 5DataType: "JSON",//data types returned by the server6Asyncfalse,//is synchronized7data:{//It is important to note that this data is passed as a parameter to the background, because it is post, so you can define multiple8"id": ID9         //" name": "Youname",//note, here is just a demonstration, preceded by a variable name, followed by a value to be passedTen         //"Age ": "Youage", One         //" Sex": "Youage", A         //"Other" : " Other" -         }, -Successfunction(data) {//callback result, if successful the         if(Data.status = = 0) {//Judging Status Codes -             //Refresh -$ ("#easyuiDatagrid"). DataGrid ("Reload")); -         } +     }, -Failurefunction(Result) { +Parent.$.messager.show ({title: "Hint", msg: "Failed, please contact administrator", timeout:3000}); A         } at});

Reference:

$.ajax () parameter detailed description: http://www.cnblogs.com/tylerdonet/p/3520862.html

Three ways to explain the difference in detail: http://www.cnblogs.com/liuling/archive/2013/02/07/sdafsd.html

Links to Ajax method sets: Http://www.runoob.com/jquery/jquery-ref-ajax.html

About the differences and use of $.get (), $.post (), $.ajax () in jquery