`for`

Question

Q:

Write a simple game asking a user to guess a randomly chosen number.

Your program will select an integer (pseudo) random number between zero and an exclusive configurable fixed upper limit e.g. 10. The user will have a configurable number of tries to guess the number in question. Each time after entering a number your program will respond with either of the following:

Congratulations, you won!

You won!

You lost!

Game over, try another run?

Game continues, either of:

Number is too low
Number is too high

The system offers a maximum number of tries e.g. 6. In the following example the system initially selected the secret number 5. A possible dialogue looks like:

Try to guess my secret number between 0 and 10:
You have 5 attempts
Input your guess:4
Value is too low
Input your guess:6
Value is too high
Input your guess:5
Congratulations, you won!

Regarding reading user input and creating random numbers please use the following recipe to get started:

package ...

import java.util.Random;
...
   public static void main(String[] args) {

       // Add some parameter here e.g. range of number to be guessed,
       // and number of tries.

      final int randomValue =          // Selecting a pseudo random value
            new Random().nextInt(11);  // between 0 and 10 (inclusive).

      // ToDo: complete the implementation
   }

Answer 1

A:

final int maxValueInclusive = 10, // Guessing a value from 0 to this value (inclusive)
          numOfUserAttempts = 5,  // User will have this number of tries guessing the random value.
                randomValue =     // Create a random value between 0
     new Random().nextInt(        // and maxValueInclusive.
     maxValueInclusive + 1);

System.out.println("Try to guess my secret number in between 0 and "
                     + maxValueInclusive + ":");

System.out.println("You have " + numOfUserAttempts + " attempts");

final Scanner scan = new Scanner(System.in));
boolean numberWasFound = false;

for (int i = 0; i < numOfUserAttempts; i++) {
  System.out.print("Input your guess:");
  final int userGuess = scan.nextInt();
  if (userGuess < randomValue) {
    System.out.println("Number is too low");
  } else if (randomValue < userGuess) {
    System.out.println("Number is too high");
  } else {
    numberWasFound = true;
    break;
  }
}

if (numberWasFound) {
  System.out.println("Congratulations, you won!");
} else {
  System.out.println("Game over, try another run?");
}

In case you don't like break statements the following variant also solves the problem:

...
boolean numberWasFound = false;

for (int i = 0; !numberWasFound && i < numOfUserAttempts; i++) {
    ...
    } else {
        numberWasFound = true;
        // No »break« statement required anymore
    }
}
...

Prev	Up	Next
Loops and calculations	Home	Smallest multiple

for

Guessing numbers

`for`