create http request javascript

function makeRequest (method, url, data) {
  return new Promise(function (resolve, reject) {
    var xhr = new XMLHttpRequest();
    xhr.open(method, url);
    xhr.onload = function () {
      if (this.status >= 200 && this.status < 300) {
        resolve(xhr.response);
      } else {
        reject({
          status: this.status,
          statusText: xhr.statusText
        });
      }
    };
    xhr.onerror = function () {
      reject({
        status: this.status,
        statusText: xhr.statusText
      });
    };
    if(method=="POST" && data){
        xhr.send(data);
    }else{
        xhr.send();
    }
  });
}

//GET example
makeRequest('GET', "https://www.codegrepper.com/endpoint.php?param1=yoyoma").then(function(data){
              var results=JSON.parse(data);
});

const Http = new XMLHttpRequest();
const url='https://jsonplaceholder.typicode.com/posts';
Http.open("GET", url);
Http.send();

Http.onreadystatechange = (e) => {
  console.log(Http.responseText)
}

var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {

    if (this.readyState == 4 && this.status == 200) {

        // Typical action to be performed when the document is ready:
       
 document.getElementById("demo").innerHTML = xhttp.responseText;

    }
};

xhttp.open("GET", "filename", true);

xhttp.send();