let request= new XMLHttpRequest();

let valasz="";

let root=document.getElementById('root');

request.open('GET','https://jsonplaceholder.typicode.com/posts',true);

request.onload=function(){
    valasz=JSON.parse(this.response);
    valasz.forEach(elem=>{
        let p=document.createElement('p');
        p.textContent=elem.title;
        root.appendChild(p);
    });
}

//request.send();

fetch('https://jsonplaceholder.typicode.com/posts')
.then(res=>res.json())
.then(valasz=>{
    valasz.forEach(elem=>{
        let p=document.createElement('p');
        p.textContent=elem.title;
        root.appendChild(p);
    })
}).catch(err=>alert(err));