Compile time error

exercise No. 273

Q:

We consider:

/**
 * Get the largest of three values
 *
 * @param a First value
 * @param b Second value
 * @param c Third value
 * @return The maximum of a, b and c
 */
public static int max (int a, int b, int c) {
  if (a < b) {
    if (b < c) {
      return c;
    } else {
      return b;
    }
  } else {
    if (a < c) {
      return c;
    }
  }
}

  1. This code contains three return statements. Nonetheless the compiler echoes a »Missing return statement«. Why ?

  2. Correct both syntactical and logical errors.

A:

  1. In case both a > b and a > c hold, no return statement will be reached. This is an error: A method having a non-void return type must return a value under all circumstances.

  2. We reorganize a little bit:

    public static int max (int a, int b, int c) {
    if (a < b || a < c) { // Either b or c will be the desired maximum
        if (b < c) {
            return c;
        } else {
            return b;
        }
    } else {
        return a;
    }
}
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