function Human(name, age, sex){
this.name = name;
this.age = age;
this.sex = sex;
}
Human.prototype.toString = function() {
return this.name + " is " + this.age + " years old";
}
function Superman(name, age, power) {
this.name = name;
this.age = age;
this.power = power;
}
Superman.prototype = new Human();
Superman.prototype.showPower = function() {
return "Superman can " + this.power;
}
var superMan = new Superman(\'Clark Kent\', 30, \'fire laser beam\');
/*
Clark Kent is 30 years old
Superman can fire laser beam
*/
console.log(superMan.toString());
console.log(superMan.showPower());