javascript http post request example

Example 1: javascript send post request

let data = {element: "barium"};

fetch("/post/data/here", {
  method: "POST", 
  body: JSON.stringify(data)
}).then(res => {
  console.log("Request complete! response:", res);
});


// If you are as lazy as me (or just prefer a shortcut/helper):

window.post = function(url, data) {
  return fetch(url, {method: "POST", body: JSON.stringify(data)});
}

// ...

post("post/data/here", {element: "osmium"});

Example 2: xmlhttp js post request

var xhr = new XMLHttpRequest();
xhr.open("POST", '/url', true);
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

xhr.onreadystatechange = function() { // Call a function when the state changes.
    if (this.readyState === XMLHttpRequest.DONE && this.status === 200) {
        // Request finished. Do processing here.
    }
}
xhr.send("name=Hello&id=world");

Example 3: js make post request

var xhr = new XMLHttpRequest();
// we defined the xhr

xhr.onreadystatechange = function () {
    if (this.readyState != 4) return;

    if (this.status == 200) {
        var data = JSON.parse(this.responseText);

        // we get the returned data
    }

    // end of state change: it can be after some time (async)
};

xhr.open('GET', yourUrl, true);
xhr.send();