JavaScript继承constructor.prototype

Question

I can't understand line 4.
If I write like derive.constructor.prototype ,
The error will occur.

And also, What is base.apply(derive, baseArgs); ?
I thought that I can do like base(baseArg) I couldn't do that.

function initializeBase(derive, base, baseArgs) {
  base.apply(derive, baseArgs);
  for(var prop in base.prototype) {
    var proto = derive.constructor.prototype;
    if(!proto[prop]) {
      proto[prop] = base.prototype[prop];
    }
  }
}

var Member = function(firstName, lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
};

Member.prototype.getName = function() {
    return this.firstName + ' ' + this.lastName;
};

var SpecialMember = function(firstName, lastName, role) {
    initializeBase(this, Member, [firstName, lastName]);

    this.role = role;
};

SpecialMember.prototype.isAdministrator = function() {
    return (this.role == 'Administrator');
};

var mem = new SpecialMember('Kotaro', 'Hayafune', 'Administrator');
document.writeln('Name: ' + mem.getName() + '<br>');
document.writeln('Administrator: ' + mem.isAdministrator());

Answer 1

Not sure what your variables contain here but usually if you want the prototype you would write:

var proto = derive.prototype;

and if you wanted the constructor you'd write:

var constr = derive.prototype.constructor;