SOURCE

function Person() {}
Person.prototype.name = 'Ni'
Person.prototype.age = 20
Person.prototype.job = 'Code'
Person.prototype.sayNmae = function(){
    console.log(this.name)
}

console.log(Object.keys(Person.prototype))

let p1 = new Person()
p1.name = 'p1'
p1.newKey = 'newkey'
console.log(Object.keys(p1))
for(const k1 in p1){
    console.log(k1)
}

console.log( Object.getOwnPropertyNames(p1))
console.log(p1.constructor)

let s = {}
console.log('s的constructor:',s.constructor)