编辑代码

function inheritPrototype(child, parent) {
	var p = Object.create(parent.prototype);
	p.constructor = child;
	child.prototype = p;
}
function Parent(name, age) {
    this.name = name;
    this.age = age;
    console.log('Parent is running.');
}
function Child(name, age) {
    Parent.apply(this, arguments);
}
inheritPrototype(Child, Parent);
var instance = new Child('Allen', 5);
Child.prototype.sex = 'male';
console.log(instance.sex);
console.log(Parent.prototype);
console.log(instance.constructor === Child);