使用XMLHttpRequest。

简单的GET请求

httpRequest = new XMLHttpRequest()
httpRequest.open('GET', 'http://www.example.org/some.file')
httpRequest.send()

简单的POST请求

httpRequest = new XMLHttpRequest()
httpRequest.open('POST', 'http://www.example.org/some/endpoint')
httpRequest.send('some data')

我们可以通过可选的第三个参数指定请求应该是异步(true)(默认值)或同步(false)。

// Make a synchronous GET request
httpRequest.open('GET', 'http://www.example.org/some.file', false)

我们可以在调用httpRequest.send()之前设置头信息

httpRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');

我们可以通过设置httpRequest来处理响应。在调用httpRequest.send()之前，onreadystatechange函数

httpRequest.onreadystatechange = function(){
  // Process the server response here.
  if (httpRequest.readyState === XMLHttpRequest.DONE) {
    if (httpRequest.status === 200) {
      alert(httpRequest.responseText);
    } else {
      alert('There was a problem with the request.');
    }
  }
}

这里有一个非常好的纯javascript解决方案

/*create an XMLHttpRequest object*/

let GethttpRequest=function(){  
  let httpRequest=false;
  if(window.XMLHttpRequest){
    httpRequest   =new XMLHttpRequest();
    if(httpRequest.overrideMimeType){
    httpRequest.overrideMimeType('text/xml');
    }
  }else if(window.ActiveXObject){
    try{httpRequest   =new ActiveXObject("Msxml2.XMLHTTP");
  }catch(e){
      try{
        httpRequest   =new ActiveXObject("Microsoft.XMLHTTP");
      }catch(e){}
    }
  }
  if(!httpRequest){return 0;}
  return httpRequest;
}

  /*Defining a function to make the request every time when it is needed*/

  function MakeRequest(){

    let uriPost       ="myURL";
    let xhrPost       =GethttpRequest();
    let fdPost        =new FormData();
    let date          =new Date();

    /*data to be sent on server*/
    let data          = { 
                        "name"      :"name",
                        "lName"     :"lName",
                        "phone"     :"phone",
                        "key"       :"key",
                        "password"  :"date"
                      };

    let JSONdata =JSON.stringify(data);             
    fdPost.append("data",JSONdata);
    xhrPost.open("POST" ,uriPost, true);
    xhrPost.timeout = 9000;/*the time you need to quit the request if it is not completed*/
    xhrPost.onloadstart = function (){
      /*do something*/
    };
    xhrPost.onload      = function (){
      /*do something*/
    };
    xhrPost.onloadend   = function (){
      /*do something*/
    }
    xhrPost.onprogress  =function(){
      /*do something*/
    }

    xhrPost.onreadystatechange =function(){

      if(xhrPost.readyState < 4){

      }else if(xhrPost.readyState === 4){

        if(xhrPost.status === 200){

          /*request succesfull*/

        }else if(xhrPost.status !==200){

          /*request failled*/

        }

      }


   }
  xhrPost.ontimeout = function (e){
    /*you can stop the request*/
  }
  xhrPost.onerror = function (){
    /*you can try again the request*/
  };
  xhrPost.onabort = function (){
    /*you can try again the request*/
  };
  xhrPost.overrideMimeType("text/plain; charset=x-user-defined-binary");
  xhrPost.setRequestHeader("Content-disposition", "form-data");
  xhrPost.setRequestHeader("X-Requested-With","xmlhttprequest");
  xhrPost.send(fdPost);
}

/*PHP side
<?php
  //check if the variable $_POST["data"] exists isset() && !empty()
  $data        =$_POST["data"];
  $decodedData =json_decode($_POST["data"]);
  //show a single item from the form
  echo $decodedData->name;

?>
*/

/*Usage*/
MakeRequest();

尝试使用Fetch Api (Fetch Api)

fetch('http://example.com/movies.json').then(response => response.json()).then(data => console.log(data));

非常清澈，100%香草味。

如果您不想包含JQuery，我建议您尝试一些轻量级AJAX库。

我最喜欢的是reqwest。它只有3.4kb，构建得非常好:https://github.com/ded/Reqwest

下面是一个带有reqwest的GET请求示例:

reqwest({
    url: url,
    method: 'GET',
    type: 'json',
    success: onSuccess
});

现在，如果您想要更轻量级的东西，我将尝试仅需0.4kb的microAjax: https://code.google.com/p/microajax/

这是所有的代码:

function microAjax(B,A){this.bindFunction=function(E,D){return function(){return E.apply(D,[D])}};this.stateChange=function(D){if(this.request.readyState==4){this.callbackFunction(this.request.responseText)}};this.getRequest=function(){if(window.ActiveXObject){return new ActiveXObject("Microsoft.XMLHTTP")}else{if(window.XMLHttpRequest){return new XMLHttpRequest()}}return false};this.postBody=(arguments[2]||"");this.callbackFunction=A;this.url=B;this.request=this.getRequest();if(this.request){var C=this.request;C.onreadystatechange=this.bindFunction(this.stateChange,this);if(this.postBody!==""){C.open("POST",B,true);C.setRequestHeader("X-Requested-With","XMLHttpRequest");C.setRequestHeader("Content-type","application/x-www-form-urlencoded");C.setRequestHeader("Connection","close")}else{C.open("GET",B,true)}C.send(this.postBody)}};

下面是一个示例调用:

microAjax(url, onSuccess);

这是一个没有JQuery的JSFiffle

http://jsfiddle.net/rimian/jurwre07/

function loadXMLDoc() {
    var xmlhttp = new XMLHttpRequest();
    var url = 'http://echo.jsontest.com/key/value/one/two';

    xmlhttp.onreadystatechange = function () {
        if (xmlhttp.readyState == XMLHttpRequest.DONE) {
            if (xmlhttp.status == 200) {
                document.getElementById("myDiv").innerHTML = xmlhttp.responseText;
            } else if (xmlhttp.status == 400) {
                console.log('There was an error 400');
            } else {
                console.log('something else other than 200 was returned');
            }
        }
    };

    xmlhttp.open("GET", url, true);
    xmlhttp.send();
};

loadXMLDoc();

xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
        alert(this.responseText);
    }
};
xhttp.open("GET", "ajax_info.txt", true);
xhttp.send();