基于原型的类继承

var Animal = function() {};

Animal.prototype.breath = function() {
    console.log('breath');
};

var Dog = function() {};

//Dog继承了Animal
Dog.prototype = new Animal;

Dog.prototype.wag = function() {
    console.log('wag tail');
};

var dog = new Dog;
dog.wag();
dog.breath(); //继承的属性

日志: wag tail
日志: breath