Table of Contents

Guessing Numbers


  • Write a program in which the computer picks a random number between 1 and 100.
  • Then as long as the user has not guessed the correct number, let the user guess a number and report whether their guess is too high or too low.
  • Then print the random number

Additional requirements:

  • Modify the “Guessing Numbers” program so that when one game has ended, the user is asked if they want to play again.
  • Play should continue until the user responds “no” to the prompt to play again


Test case 1:
Input: User guesses -1 (not an integer you'd normally expect)
Expected Output: Too low
Actual Output: Too low
Test case 2:
Input: User guesses "BBQ sauce" (not an integer at all)
Expected Output: Reprompt the user
Actual Output: reprompts the user
Test case 3:
Input: User guesses 50 (valid number)
Expected Output: Too low or too high
Actual Output: Varied appropriately
#include <iostream>
#include <ctime>
#include <string>
using namespace std;
const int MIN_RAND_NUM = 0;
const int MAX_RAND_NUM = 100;
int main()
	// inputs: user guesses
	// outputs: too high/low, computer's number
	//This must be defined outside the loop in order to use it in the loop condition, but it is modified in the loop.
	string input;
	// This is the loop around the whole program 
		// Computer picks a random number
		srand(time(0)); // Make rand() generate random and not pseudorandom numbers
		int random_number = rand() % (MAX_RAND_NUM - MIN_RAND_NUM + 1) + MIN_RAND_NUM;
		// uncommenting the following line would give away the computer's random number!
		// cout << "My random integer is " << random_number << endl;
		int user_input = -1;
		// Let the user start guessing
			// Each loop executes one guess
			cout << "Gimme your best shot: ";
			cin >> user_input;
			while ( // tried to read an integer, but found something else in cin buffer
				cout << "That's bad. Gimme another: ";
				string dummy_input; // used to consume bad input that's sitting in cin
				cin.clear(); // clears the "red light" on cin that's telling me there's a problem
				cin >> dummy_input; // consumes bad input that's sitting in cin
				cin >> user_input; // waits for new input
			if (user_input < random_number)
				cout << "TOO LOW!" << endl;
			else if (user_input > random_number) // simply using an else here would not work. Why not?
				cout << "TOO HIGH!" << endl;
		} while (user_input != random_number);
		// until he/she gets the random number
		// Print out the random number
		cout << "That's right! My number was " << random_number << "!" << endl;
		cout << "Play again (Y/N) :)?" << endl;
		cin >> input;
	} while (input == "Y");
	return 0;
cs-142/guessing-numbers.txt · Last modified: 2015/05/12 19:00 by cs142ta
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