I want to merge all data in two arraylist in c#. Some data in arraylist got same with another arraylist. i don't want duplicate data when merge.

```
ArrayList1   ArrayList2
    1             1
    2             2
    3             4
                  5

```

I've try the coding below. but the result not as i expected:

```
for(int i = 0; i<arrayList2;i++)
{
  for(int j = 0; j<arrayList1;j++)
  {
     if(arraylist1[i] == arraylist2[j])
     {
        newArraylist.add(arraylist[i]+"-same");
     }
     else
     {
        newArraylist.add(arraylist[i]+"-from arrayList2");
     }
  }
}

```

The result from code above is :

```
newArrayList
   1 - same
   2 - same
   4 - from arraylist2
   5 - from arraylist2

```

the result that i want :

```
 newArrayList
       1 - same
       2 - same
       3 - from arraylist1
       4 - from arraylist2
       5 - from arraylist2

```