Remove occurrences of duplicate words in a string

Question

Take the following string as an example:

var string = \"spanner, span, spaniel, span\";

From this string I would like to find the duplicate

Answer 1

this code block will remove duplicate words from a sentence.

the first condition of if statement i.e (i==arr.indexOf(arr[i])) will include the first occurence of a repeating word to the result(variale unique in this code).

the second condition (arr.indexOf(arr[i])==arr.lastIndexOf(arr[i])) will include all non repeating words.