JS: How can a new object inherit Array from prototype?

<code><script type="text/javascript"> 

function Person(){} 

Person.prototype.array = new Array("Koji", "Luo"); 

Person.prototype.showArray = function(){ 
alert(this.array); 
} 

var obj1 = new Person(); //生成一个Person对象 
var obj2 = new Person(); 

obj1.array.push("Kyo"); //向obj1的array属性添加一个元素 

obj1.showArray(); //Koji,Luo,Kyo 
obj2.showArray(); //Koji,Luo,Kyo 

</script> </code>

If an element is added to the array of obj1, it will also be added to the array of obj2.
Is the array they inherit a pointer? Everyone has the array in the prototype object?

<code>//最后问一个很奇怪的问题(prototype中的array难道也只是一个指针?)
</code>

Thank you everyone..