js定义函数：

<script> function A() {} let a1 = new A(); let a2 = new A(); // 为A类添加原型 => 类似于类属性 A.prototype.num = 100; console.log(a1.num); console.log(a2.num); </script>

ES6语法下类

class B { constructor(name) { this.name = name; } } let b1 = new B(‘Tom‘); let b2 = new B(‘Ben‘); B.prototype.count = 666; console.log(b1.count); console.log(b2.count); console.log(b1.name); console.log(b2.name);

js原型补充

，