how to make api which can fetch data code example

Example 1: get data from fetch api into variable

<script>
function getFromAPI(url, callback){
  var obj;
  fetch(url)
    .then(res => res.json())
    .then(data => obj = data)
    .then(() => callback(obj))
 }

getFromAPI('https://jsonplaceholder.typicode.com/posts', getData);

function getData(arrOfObjs){
  var results = "";
  arrOfObjs.forEach( (x) => {
    results += "<p> Id: " + x.id + "<ul>"
    Object.keys(x).forEach( (p) => {
        results += "<li>" + (p + ": " + x[p]) + "</li>";
    });
    results += "</ul> </p> <hr>"
  })
  results += "";
  document.getElementById("myDiv").innerHTML = results;
}

</script>

Example 2: fetch api tutorial

fetch('https://api.github.com/users/manishmshiva', {
  method: "GET",
  headers: {"Content-type": "application/json;charset=UTF-8"}
})
.then(response => response.json()) 
.then(json => console.log(json)); 
.catch(err => console.log(err));