谁来看看怎么回事，关于javascript的，求改进，去重复

[sun342115450]

<script language="javascript">
var arr=new Array(2,3,23,32,32,23,56,73);
var temp;
document.write("去掉重复的数以前：")
document.write(arr)
for(var i=0;i<arr.length-1;i++)
{
for(var j=i+1;i<arr.length;j++)
{
if(arr[i]==arr[j]){
temp=arr[length-1];
arr[length-1]=arr[i];
arr[i]=temp;

}
arr.pop( );
}
}
document.write("去掉重复的数以后：")
document.write(arr);
</script>

[MuBeiBei]

<script language="javascript">
var arr=new Array(2,3,23,32,32,23,56,73);
var temp;
document.write("去掉重复的数以前：")
document.write(arr)
 Array.prototype.unique = function() 
  { 
    var a = {}; 
     for(var i=0; i<this.length; i++) 
    { 
      if(typeof a[this[i]] == "undefined") 
        a[this[i]] = 1; 
    } 
    this.length = 0; 
    for(var i in a) 
      this[this.length] = i; 
    return this; 
  } 
arr.unique()
document.write("去掉重复的数以后：")
document.write(arr);
</script>

[打字员]

Array.prototype.unique = function() {
    var temp = this.slice(0).sort();
    var index = 0;
    while(index < temp.length - 1) {
        if(temp[index] == temp[index + 1]) {
            splice(index, 1);
        } else {
            index += 1;
        }        
    }
    return temp;
} 
var arr=new Array(2,3,23,32,32,23,56,73);
arr = arr.unique();