Prova DBO-2015 1ro Bim Questão #1

StringUtil.java

public class StringUtil {
  public static String trimLeft(String string) {
    char[] chars = string.toCharArray();
    int i = 0;
    for (; i < chars.length; i++) if (chars[i] != ' ') break;
    return new String(subArray(chars, i, chars.length));
  }
  public static String trimRight(String string) {
    char[] chars = string.toCharArray();
    int i = chars.length - 1;
    for (; i > 0; i--)
      if (chars[i] != ' ')
        break;
    return new String(subArray(chars, 0, i + 1));
  }

  public static String trim(String string) {
    return trimLeft(trimRight(string));
  }
  public static boolean eq(String string1, String string2) {
    char[] chars1 = string1.toCharArray();
    char[] chars2 = string2.toCharArray();
    if (chars1.length != chars2.length) return false;
    for (int i = 0; i < chars1.length; i++)
      if (chars1[i] != chars2[i])
        return false;
    return true;
  }
  private static char[] subArray(char[] array, int start, int end) {
    char[] narray = new char[end - start];
    for (int i = start; i < end; i++)
      narray[i - start] = array[start + (i - start)];
    return narray;
  }
  public static void main(String[] args) {
    // Aparar String à esquerda: remover espaços à esquerda da String
    System.out.println(eq(trimLeft("    abc  "), "abc  "));
    System.out.println(eq(trimLeft("      "), ""));
    System.out.println(trimLeft(" A ").toCharArray().length == 2);
    System.out.println(eq(trimLeft("left"), "left"));
    // Aparar String à direita: remover espaços à direita da String
    System.out.println(eq(trimRight("    abc  "), "    abc"));
    System.out.println(eq(trimRight("      "), ""));
    System.out.println(eq(trimRight("right"), "right"));
    // Aparar String em ambos lados
    System.out.println(eq(trim("    abc  "), "abc"));
    System.out.println(eq(trimRight("both"), "both"));
    System.out.println(eq(trimRight(" bo  th  "), "bo  th"));
  }
}