# 5.x — Chapter 5 comprehensive quiz

Quick review

If statements allow us to execute a statement based on whether some condition is true. Else statements execute if the associated if statement is false. You can chain together multiple if and else statements.

Switch statements provide a cleaner and faster method for selecting between a number of discrete items. Switch statements pair great with enumerations.

Goto statements allow the program to jump to somewhere else in the code. Don’t use these.

While loops allow the program to loop as long as a given condition is true. The condition is evaluated before the loop executes.

Do while loops are the same as while loops, but the condition is evaluated after the loop execution. They’re great for menus or things that need to execute at least once.

For loops are the most used loop, and are perfect when you need to loop a specific number of times.

Break statements allow us to break out of a switch, while, do while, or for loop. Or a for each loop, which we haven’t covered yet.

Continue statements allow us to move immediately to the next loop iteration. Be careful when using these with while and do while loops, as your loop counter may not get incremented properly.

And finally, random numbers give us a way to make our programs behave different each time they are run. We’ll see an example of this in the quiz below!

Quiz time!

Warning: The quizzes start getting harder from this point forward, but you can do it. Let’s rock these quizzes!

1) In the chapter 2 comprehensive quiz, we wrote a program to simulate a ball falling off of a tower. Because we didn’t have loops yet, the ball could only fall for 5 seconds.

Take the program below and modify it so that the ball falls for as many seconds as needed until it reaches the ground.

In constants.h:

Show Solution

2a) Implement a game of hi-lo. First, your program should pick a random integer between 1 and 100. The user is given 7 tries to guess the number.

If the user does not guess the correct number, the program should tell them whether they guessed too high or too low. If the user guesses the right number, the program should tell them they won. If they run out of guesses, the program should tell them they lost, and what the correct number is. At the end of the game, the user should be asked if they want to play again. If the user doesn’t enter ‘y’ or ‘n’, ask them again.

Note: You do not need to implement error handling for the user’s guess.

Here’s what your output should look like:

```Let's play a game.  I'm thinking of a number.  You have 7 tries to guess what it is.
Guess #1: 64
Guess #2: 32
Guess #3: 54
Guess #4: 51
Correct! You win!
Would you like to play again (y/n)? y
Let's play a game.  I'm thinking of a number.  You have 7 tries to guess what it is.
Guess #1: 64
Guess #2: 32
Guess #3: 54
Guess #4: 51
Guess #5: 36
Guess #6: 45
Guess #7: 48
Sorry, you lose.  The correct number was 49.
Would you like to play again (y/n)? q
Would you like to play again (y/n)? f
Would you like to play again (y/n)? n
Thank you for playing.
```

Hints:
* If your compiler is C++11 capable, use the Mersenne Twister algorithm from chapter 5.9 -- Random number generation to pick a random number.
* If your compiler is not C++11 capable, you can use rand() (also presented in chapter 5.9 -- Random number generation) to pick a random number
* Write a function that allows the user to play a single game of hi-lo.
* Write a function that asks the user if they want to play again and handles the looping logic for an incorrect input.

Show Solution

2b) Update your previous solution to handle invalid input (e.g. ‘x’) or valid input with extraneous characters (e.g. “43x”) when the user is guessing a number.

Hint: Write a separate function to handle the user inputting their guess (along with the associated error handling).

Show Solution

 6.1 -- Arrays (Part I) Index 5.11 -- Introduction to testing your code

### 485 comments to 5.x — Chapter 5 comprehensive quiz

• Isac Svensson

Hey!

Just completed quiz 1 and where going to make the program robust, but for some reason I cant get it to loop back to the start of the while statment.

Can someone tell me what I'm doing wrong?

• * Line 30, 31, 45, 46, 47: Initialize your variables with uniform initialization. You used copy initialization.
* Line 9: Initialize your variables with uniform initialization.
* Line 30, 38, 40: Limit your lines to 80 characters in length for better readability on small displays.
* Line 14: Don't pass 32767 to @std::cin.ignore. Pass @std::numeric_limits<std::streamsize>::max().

Please elaborate. What are you trying to do? What is happening?

• Isac Svensson

Hi!

Is this better?

When I input an "a" for example my program prints:

You have input an invalid value
Enter the height of a tower in meters: Enter the height of a tower in meter:

Why is it printed twice?

After i sow the solution I just felt bad.I just made it long for no reason.But I wanted to implement things that I've learned so far.
Some advice will be much appreciated 🙂
And big thanks to you nascardriver for commenting my moody codes
And ofcourse Alex for this site 🙂

• Hi!

* Line 67: Initialize
* @clearBuffer

* Line 98: Initialize @std::string with empty curly brackets. The default constructor is faster than the others.
* Line 150: Could be static
* Line 150: Uniform initialization
* Line 157 should be moved below line 160 so it can be initialized with @setSettings. @setSettings could call @generateRandomNumber itself.
* @askGameDifficulty should make use of @getDifficultyString
* Inconsistent formatting. Use your editors auto-formatting feature.
* @printAndGetGuess: How do you know that there's no extra input before line 208, and that there is in line 210 and 217?
* Line 274, 277: Those could print numbers that are out of range if max - min < 20. They need to be clamped to @min/@max (See @std::min and @std::max).
* Don't use @exit
* Line 342: Initialize everything to 0. For chars, use 0 or '\0'
* Line 466, 367: Initialize