Java > Warmup-1 > missingChar (CodingBat Solution)

Problem:

Given a non-empty string and an int n, return a new string where the char at index n has been removed. The value of n will be a valid index of a char in the original string (i.e. n will be in the range 0..str.length()-1 inclusive).

missingChar("kitten", 1) → "ktten"
missingChar("kitten", 0) → "itten"
missingChar("kitten", 4) → "kittn"

Solution:

//Well, we can make do with just creating a method
//that will return us a modified string that will take
//in our String and index
public String missingChar(String str, int n) {
  //We can't remove things from a String variable, just add
  //to it so we have to make a new string by taking two
  //'slices' or substrings of that String but without including
  //a certain index.
  //Note: str.substring(a,b) gives us a new String starting
  //from index 0 to index b-1, which is why n isn't in the new
  //string and why length() doesn't cause any problems
  return str.substring(0,n) + str.substring(n+1,str.length());
     }