Javascript JSON取得

Question

   var req = new XMLHttpRequest();
    req.open('GET','data.json', true);
    //req.responseType = 'json';
    req.send();
   
    var json = JSON.parse(req.responseText);
    var $timeline = $('ul.timeline');

    json.forEach(function(item){
  
      $timeline.append(
      '<li>' +
        '<div class="timeline-image">' +
          '<img class="rounded-circle img-fluid" src="' + item.imgPath + '" alt="">' + 
        '</div>' +
        '<div class="timeline-panel">' + 
          '<div class="timeline-heading">' + 
            '<h4>' + item.time + '</h4>' + 
            '<h4 class="subheading">' + item.title + '</h4>' +
          '</div>' +
          '<div class="timeline-body">' +
            '<p class="text-muted">' + item.description + '</p>' + 
          '</div>' +
        '</div>' +
      '</li>' 
      );
  });

[
	{
		"id": 1,
		"imgPath": "img/about/1.jpg",
		"time": "2009-2011",
		"title": "Our Humble Beginnings",
		"description": "Lorem ipsum dolor sit amet, consectetur adipisicing elit. Sunt ut voluptatum eius sapiente, totam reiciendis temporibus qui quibusdam, recusandae sit vero unde, sed, incidunt et ea quo dolore laudantium consectetur!"
	},
	{
		"id": 2,
		"imgPath": "img/about/2.jpg",
		"time": "March 2011",
		"title": "An Agency is Born",
		"description": "Lorem ipsum dolor sit amet, consectetur adipisicing elit. Sunt ut voluptatum eius sapiente, totam reiciendis temporibus qui quibusdam, recusandae sit vero unde, sed, incidunt et ea quo dolore laudantium consectetur!"
	},
	{
		"id": 3,
		"imgPath": "img/about/3.jpg",
		"time": "December 2012",
		"title": "Transition to Full Service",
		"description": "Lorem ipsum dolor sit amet, consectetur adipisicing elit. Sunt ut voluptatum eius sapiente, totam reiciendis temporibus qui quibusdam, recusandae sit vero unde, sed, incidunt et ea quo dolore laudantium consectetur!"
	},
	{
		"id": 4,
		"imgPath": "img/about/4.jpg",
		"time": "July 2014",
		"title": "Phase Two Expansion",
		"description": "Lorem ipsum dolor sit amet, consectetur adipisicing elit. Sunt ut voluptatum eius sapiente, totam reiciendis temporibus qui quibusdam, recusandae sit vero unde, sed, incidunt et ea quo dolore laudantium consectetur!"
	}
]

現在、以下のエラーが出てきます。
VM1862:1 Uncaught SyntaxError: Unexpected end of JSON input
at JSON.parse (<anonymous>)

https://qiita.com/qwq00/items/9cd8b8e095bea0633a88

このサイトのように、JSON.parse(req.responseText || "null")にしました。

しかし、以下のエラーできました。JSONファイルの内容が取得出来ていないと思います。
なにか、アドバイスお願いいたします。

Uncaught TypeError: Cannot read property 'forEach' of null

Answer 1

JSON.parse(req.responseText || "[]")としてみては。