1、
2、
function Parent(value) {
this.val = value
}
Parent.prototype.getValue= function() {
console.log(this.val)
}
function Child(value) {
Parent.call(this, value)
}
Child.prototype = Object.create(Parent.prototype, {
constructor: {
value: Child,
enumerable: false,
writable: true,
configurable: true
}
})
const child = new Child(1)
child.getValue() // 1
child instanceof
Parent // true
3、关于2的优化理解
const person = {
isHuman: false,
printIntroduction: function() {
console.log(`My name is ${this.name}. Am I human? ${this.isHuman}`);
}
};
const me = Object.create(person);
me.name = 'Matthew'; // "name" is a property set on "me", but not on "person"
me.isHuman = true; // inherited properties can be overwritten
me.printIntroduction();
// expected output: "My name is Matthew. Am I human? true"
console.log(person.isHuman)//false
这里推测是writable和configureable导致的结果。有待更新。
4、
