變量只能保留對對象的引用﹐所以b=a這一句把原來的b對象丟給了垃圾回收器﹐而b對象引用起來a對象了。如果你想複製對象可以提供一個複製方法﹕<script>
function MyObject(){
this.theid="id_value";
this.thename="name_value";
this.thevalue="value_value";
this.clone = function(){
var obj = new MyObject();
obj.theid=this.theid;
obj.thename=this.thename;
obj.thevalue=this.thevalue;
return obj;
}
}var a=new MyObject();
var b=a.clone();alert(a.theid);
alert(b.theid);a.theid="id_a";alert(a.theid);
alert(b.theid);
</script>