9. Class

构造函数尽可能使用 Class 的形式

  1. // 例子 9-1
  2.  
  3. class Foo {
  4.   static bar () {
  5.     this.baz();
  6.   }
  7.   static baz () {
  8.     console.log('hello');
  9.   }
  10.   baz () {
  11.     console.log('world');
  12.   }
  13. }
  14.  
  15. Foo.bar(); // hello
  1. // 例子 9-2
  2.  
  3. class Shape {
  4.   constructor(width, height) {
  5.     this._width = width;
  6.     this._height = height;
  7.   }
  8.   get area() {
  9.     return this._width * this._height;
  10.   }
  11. }
  12.  
  13. const square = new Shape(10, 10);
  14. console.log(square.area);    // 100
  15. console.log(square._width);  // 10