副本以JavaScript

下面的JavaScript代码[jsfiddle]：副本以JavaScript

Array.prototype.remove = function(from, to) { 
    var rest = this.slice((to || from) + 1 || this.length); 
    this.length = from < 0 ? this.length + from : from; 
    return this.push.apply(this, rest); 
}; 

var masterlist = [{ 
    name: "Master1"}, 
{ 
    name: "Master2"}]; 
var parentlist = [{ 
    name: "Parent1"}, 
{ 
    name: "Parent2"}]; 
var childlist = [{ 
    name: "Child1"}, 
{ 
    name: "Child2"}]; 

for (var i = 0; i < masterlist.length; i++) { 
    var master = masterlist[i]; 
    master.parents = parentlist.slice(); 
    for (var j = 0; j < master.parents.length; j++) { 
     var parent = master.parents[j]; 
     parent.children = childlist.slice(); 
    } 
} 

console.log("before removing") 
console.log("master1 parents: " + masterlist[0].parents.length); 
console.log("master2 parents: " + masterlist[1].parents.length); 
console.log("master1 parent 1 childrens: " + masterlist[0].parents[0].children.length); 
console.log("master2 parent 2 childrens: " + masterlist[1].parents[1].children.length); 

masterlist[0].parents.remove(0); 
masterlist[0].parents[0].children.remove(0); 

console.log("after removing") 
console.log("master1 parents: " + masterlist[0].parents.length); 
console.log("master2 parents: " + masterlist[1].parents.length); 
console.log("master1 parent 1 childrens: " + masterlist[0].parents[0].children.length); 
console.log("master2 parent 2 childrens: " + masterlist[1].parents[1].children.length);?

结果：

除去
master1父母前：2
master2父母：2
master1家长1儿童：2
master2家长2儿童：2
删除后
master1父母：1
master2父母：2
master1父1名儿童：1个
master2父2名儿童：在删除之前

：1

我希望（和必要性）本
master1父母：2
master2父母：2
master1父母1儿童：2
master2父母2儿童：1
master2父母：2
master1父1名儿童：1个
master2父2名儿童：2
去除
master1父母后2 < - 差异