good case

hoisting_exam_06.js

// <input type="text" id="email">
// <input type="text" id="name">
// <input type="text" id="phone">
// <div id="notice"></div>

function show(text) {
  document.getElementById('notice').innerHTML = text;
}

function set() {
  var a = [
    {id: 'email', text: 'email'},
    {id: 'name', text: 'name'},
    {id: 'phone', text: 'phone'},
  ];
  for (var i = 0; i < a.length; i++) {
    let item = a[i];
    document.getElementById(item.id).onfocus = function(text) {
      return function() {
        show(text);
      };
    } (item.text);
  }
}

set();