Algorithms for removing duplicate data _ basics

There is a problem at work: given a sorted array (ascending), delete the duplicate data in the array, but only one array can be used, and the size of the array may vary.
Example: array: [1,1,2,2,3,3,4,5,7,10]
Output:: [1,2,3,4,5,7,10]
Implementation (1):
var arr =new Array (1,1,2,2,3,3,4,5,7,10);
var len = arr.length;
for (Var i=len-1;i>=1;i--)
{
if (arr[i-1] = = Arr[i])
{
Arr.splice (i,1);
}
}
Alert (arr);

Implementation (2):
var arr =new Array (1,1,2,2,3,3,4,5,7,10); var len = Arr.length;var k=0;for (var i=1;i<len;i++) {if (arr[k)!= arr[i           ]) {arr[k+1]=arr[i];        k++; }}alert (arr);
But the performance is not the best, and I don't know if you have a better algorithm. (The implementation language can be javascript,c#,vb.net,.....)