on 17-Aug-2014 (Sun)

Suppose we have a class that tries to cooperate with String. What is wrong with it?

public final class CaseInsensitiveString {

    private final String s;

    @Override public boolean equals(Object o) {
        if (o instanceof CaseInsensitiveString)
            return s.equalsIgnoreCase(((CaseInsensitiveString) o).s);
        if (o instanceof String)
            return s.equalsIgnoreCase((String) o);
       return false;
    }

    // rest of the code
}

for (i <- 0 to 2)
  print(greetStrings(i))

1. The line in question ends [...].
2. The next line begins with a word that cannot start a statement.
3. The line ends while inside parentheses (...) or brackets [...], because these cannot contain multiple statements anyway.

1. The line in question ends in a word that would not be legal as the end of a statement, such as a period or an infix operator.
2. The next line begins [...].
3. The line ends while inside parentheses (...) or brackets [...], because these cannot contain multiple statements anyway.

1. The line in question ends in a word that would not be legal as the end of a statement, such as a period or an infix operator.
2. The next line begins with a word that cannot start a statement.
3. The line ends while [...].

class Rational(n: Int, d: Int) {
  println("Created "+ n +"/"+ d)
}

class Rational(n: Int, d: Int) {
  println("Created "+ n +"/"+ d)
}

class Rational(n: Int, d: Int) {
  require(d != 0)
  println("Created "+ n +"/"+ d)
}

class Rational(n: Int, d: Int) { // This won’t compile
  require(d != 0)
  override def toString = n +"/"+ d
  def add(that: Rational): Rational =
  new Rational(n * that.d + that.n * d, d * that.d)
}