title: I don't understand the `get` keyword for getters in JS class declarations
body: <p>Here is a JS class.</p>
  
  <pre><code>class Rectangle {
      constructor(height, width) {
        this.height = height;
        this.width = width;
      }
      // Getter
      get area() {
        return this.calcArea();
      }
      // Method
      calcArea() {
        return this.height * this.width;
      }
    }
  
    const square = new Rectangle(10, 10);
  
    console.log(square.area); // 100
  </code></pre>
  
  <p>It seems to work fine. However, I don't understand why we need to specify the <code>get</code> keyword for <code>area()</code> but not for <code>calcArea()</code> although both are returning values. Could someone explain this? And if possible, if someone could also explain this from react's perspective and whether this still applies for class components? Thanks.</p>