Remove duplicates from a list (in vim)

Question

This is my list:

['02', '03', '03', '16', '17', '17', '28', '29', '29']

I would like to know how I can remove the duplicates from this list.

Would it be also possible when I add an item to the list to check if the item is already in the list (to avoid duplicates?)

Answer 1

Try

let list=['02', '03', '03', '16', '17', '17', '28', '29', '29']
let unduplist=filter(copy(list), 'index(list, v:val, v:key+1)==-1')

. For the second question, see :h index().

By the way, if

1. all list items are strings;
2. there is no empty strings possible;
3. you don't care about order of list items

then you should probably use a Dictionary instead: for large number of strings searching for duplicates is faster (and really not required).