Java quiz questions

What will be printed?

boolean value = Double.NaN == Double.NaN;
System.out.println(value);

1. true

2. false

What will be printed?

boolean value = -0.0 == 0.0;
System.out.println(value);

1. true

2. false

What will be printed?

double value = -0.0;
System.out.println(value);

1. -0.0

2. 0

3. 0.0

4. -0

5. NaN

What will be printed?

int i = 255;
byte b = (byte) i;
System.out.println(b);

1. 255

2. -1

3. NaN

4. -255

5. -127

What is wrong with this code?

public String readLine() {
    try {
      BufferedReader br = 
         new BufferedReader(new FileReader("file.txt"));
      String line = br.readLine();
      br.close();
      return line;
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
}

1. exception is not declared

2. more specific exception type must be used in catch

3. potential resource leak

4. return must be outside of the try block

What is the outcome?

int value = (int) 2.0 / 3.0;
System.out.println(value);

1. 0

2. 1

3. 0.0

4. Type mismatch: cannot convert from double to int

What will be printed?

double value = 2 / 3;
System.out.println(value);

1. 0

2. 0.0

3. 0.6666666666666666

4. 1

5. 1.0