Java > Warmup-1 > frontBack (CodingBat Solution)

Problem:

Given a string, return a new string where the first and last chars have been exchanged.

frontBack("code") → "eodc"
frontBack("a") → "a"
frontBack("ab") → "ba"

Solution:

public String frontBack(String str) {
   if (str.length() <= 1) 
     return str;
     
  String mid = str.substring(1, str.length()-1);
  return str.charAt(str.length()-1) + mid + str.charAt(0);
}