Another method that might be desired is one that updates the Student’s number of credit hours. This method will receive a number of credit hours and add these to the Student’s current hours. Which of the following methods would accomplish this?

a) public int updateHours( )

{

return hours;

}



b) public void updateHours( )

{

hours++;

}



c) public updateHours(int moreHours)

{

hours += moreHours;

}



d) public void updateHours(int moreHours)

{

hours += moreHours;

}



e) public int updateHours(int moreHours)

{

return hours + moreHours;

}



The Coin class, as defined in Chapter 4, consists of a constructor, and methods flip, isHeads and toString. The method isHeads returns true if the last flip was a Heads, and false if the last flip was a Tails. The toString method returns a String equal to "Heads" or "Tails" depending on the result of the last flip. Using this information, answer questions 4-5.






4) A set of code has already instantiated c to be a Coin and has input a String guess, from the user asking whether the user guesses that a coin flip will result in "Heads" or "Tails". Which of the following sets of code will perform the coin flip and see if the user’s guess was right or wrong?

a) c.flip( );

if(c.isHeads( ).equals(guess)) System.out.println("User is correct");



b) if(c.flip( ).equals(guess)) System.out.println("User is correct");



c) if(c.isHeads( ).equals(guess)) System.out.println("User is correct");



d) c.flip( );

if(c.toString( ).equals(guess)) System.out.println("User is correct");



e) c.flip( ).toString( );

if(c.equals(guess)) System.out.println("User is correct");





5) What does the following code compute?

int num = 0;

for(int j = 0; j < 1000; j++)

{

c.flip( );

if(c.isHeads()) num++;

}

double value = (double) num / 1000;

a) the number of Heads flipped out of 1000 flips

b) the number of Heads flipped in a row out of 1000 flips

c) the percentage of heads flipped out of 1000 flips

d) the percentage of times neither Heads nor Tails were flipped out of 1000 flips

e) nothing at all