Need to filter out repeating consecutive characters in a string using JavaScript

Question

It is one of the challenges in Codewars, and I am supposed to write a function that will take a string and return an array, in which I can't have two consecutive identical elements. Also, the order should not change.

For example, if I pass a string

"hhhhheeeelllloooooohhheeeyyy"

, then the function should return an

array = ["h","e","l","o","h","e","y"]

.

This is my code.

    var uniqueInOrder=function(iterable){

  //your code here - remember iterable can be a string or an array

     var unique = [];

   for( var i = 0; i < iterable.length; i++) {

      unique.push(iterable[i]);

   } 



   for( var j = 0, k = 1; j < unique.length; j++, k = j + 1 ){

      if(unique[j] === unique[k]){

         unique.splice(k,1);

     }

    }

   return unique;

 }

so, if I pass a string, such as

"hhhhheeeeeellllloooo"

,it doesn't work as I intend it to because the value of

j

keeps incrementing, hence I can't filter out all the identical elements.

I tried tweaking the logic, such that whenever the

unique[j] === unique[k]

the value of j would become zero, and if that's not the case, then things would continue as they are supposed to do.

This got me an infinite loop.

I need your help.

Answer 1

The second for loop is fail because unique.length is not constant during the run. I think your problem can be solved like this:

var temp = iterable[0];
unique.push(iterable[0]);
for( var i = 1; i < iterable.length; i++) {
   if(iterable[i] != temp) {
       unique.push(iterable[i]);
       temp = iterable[i];
   }
}

Hope it helps!

Need to filter out repeating consecutive characters in a string using JavaScript

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