Remove duplicate characters from string

Question

I have to make a function in JavaScript that removes all duplicated letters in a string. So far I\'ve been able to do this: If I have the word \"anaconda\" it shows me as a

Answer 1

1. If you want your function to just return you a unique set of characters in your argument, this piece of code might come in handy. Here, you can also check for non-unique values which are being recorded in 'nonUnique' titled array:

   function remDups(str){
       if(!str.length)
           return '';
       var obj = {};
       var unique = [];
       var notUnique = [];
       for(var i = 0; i < str.length; i++){
           obj[str[i]] = (obj[str[i]] || 0) + 1;
       }
       Object.keys(obj).filter(function(el,ind){
           if(obj[el] === 1){
               unique+=el;
           }
           else if(obj[el] > 1){
               notUnique+=el;
           }
       });
   return unique;
   }
   console.log(remDups('anaconda')); //prints 'cod'
   

2. If you want to return the set of characters with their just one-time occurrences in the passed string, following piece of code might come in handy:

   function remDups(str){
       if(!str.length)
           return '';
       var s = str.split('');
       var obj = {};
       for(var i = 0; i < s.length; i++){
           obj[s[i]] = (obj[s[i]] || 0) + 1;
       }
       return Object.keys(obj).join('');
   }
   console.log(remDups('anaconda')); //prints 'ancod'