React元素的方法在map（）函数中绑定时显示奇怪的行为

I am in the early days of learning ReactJS and came across very puzzling (and annoying!) issue when rendering multiple elements with Array.prototype.map() method. I've searched for the solution around the web and had a look at couple of books with no success. Here's the code that I am trying to implement:I am in the early days of learning ReactJS and