Write a function to return the longest common prefix between two strings.
Sigiloso
// longest prefix public String longestPrefix(String s1, String s2) { int iCommon = 0; for (int i = 0; i <= Math.min(s1.length(),s2.length());i++) { if (s1.charAt(i) != s2.charAt(i)) { break; }else { iCommon++; } } return s1.substring(0,iCommon); }