package strings;

public class CharactersSame {

 /** Driver Code */
 public static void main(String[] args) {
 assert isAllCharactersSame("");
 assert !isAllCharactersSame("aab");
 assert isAllCharactersSame("aaa");
 assert isAllCharactersSame("11111");
 }

 /**
 * check if all the characters of a string are same
 *
 * @param s the string to check
 * @return {@code true} if all characters of a string are same, otherwise {@code false}
 */
 public static boolean isAllCharactersSame(String s) {
 for (int i = 1, length = s.length(); i < length; ++i) {
 if (s.charAt(i) != s.charAt(0)) {
 return false;
 }
 }
 return true;
 }
}