Slide 1Slide 2Slide 36.8 Case Study: Game of Chance and Introducing enumSlide 5Slide 5Slide 6Slide 7In-Class ExerciseGood Programming Practice 6.1 Good Programming Practice 6.2 Good Programming Practice 6.3 Common Programming Error 6.9 Common Programming Error 6.10 Slide 15COSC 181 – Foundations of Computer ProgrammingClass 2226.7 Case Study: Random Number Generation (Cont.)Scaling and shifting random numbersTo obtain random numbers in a desired range, use a statement likenumber = shifting Value + rand() % scalingF actor;shif tingValue is equal to the first number in the desired range of consecutive integersscalingFactor is equal to the width of the desired range of consecutive integersnumber of consecutive integers in the range3In-Class ExerciseUse a loop to read in a series of numbers from the user.Each time the user enters a number, your program should generate a random number chosen from the range x to x+10 where x is the current user entered numberThe program should print out the randomly selected number before asking for the next user entered number.46.8 Case Study: Game of Chance and Introducing e n u mEnumerationA set of integer constants represented by identifiersThe values of enumeration constants start at 0, unless specified otherwise, and increment by 1The identifiers in an enum must be unique, but separate enumeration constants can have the same integer valueDefining an enumerationKeyword enum A type nameComma-separated list of identifier names enclosed in bracesExample•enum Months { JAN = 1, FEB, MAR, APR };51 // Fig. 6.11: f ig06_11.cpp2 / / Craps s imulat ion.3 #include <iostream>4 us ing std::cout;5 us ing std::endl;67 #include <cstdlib> // contains prototypes for functions srand and rand8 us ing std::rand;9 us ing std::srand;1011 #inc lude <ctime> // contains prototype for function time12 us ing std::time; 1314 int rollDice(); // rolls dice, calculates amd displays sum1516 int main()17 {18 // enumeration with constants that represent the game status 19 enum Status { CONTINUE, WON, LOST }; // all caps in constants2021 int myPoint; // point if no win or loss on first roll22 Status gameStatus; // can contain CONTINUE, WON or LOST2324 // randomize random number generator using current time25 srand( time( 0 ) ); 2627 int sumOfDice = rollDice(); // first roll of the diceOutlinefig06_11.cpp (1 of 4)#include and using for function timeEnumeration to keep track of the game statusDeclaring a variable of the user-defined enumeration typeSeeding the random number generator with the current time62829 / / determine game status and point ( if needed) based on f ir s t ro l l30 switch ( sumOfDice ) 31 {32 case 7: // win with 7 on first roll33 case 11: // win with 11 on first roll 34 gameStatus = WON ;35 break;36 case 2: // lose with 2 on first roll37 case 3: // lose with 3 on first roll38 case 12: // lose with 12 on first roll 39 gameStatus = LOST;40 break;41 default: // did not win or lose, so remember point42 gameStatus = CONTINUE ; // game is not over43 myPoint = sumOfDice; // remember the point44 cout << "Po int is " << myPoint << endl;45 break; // optional at end of switch 46 } // end switch 4748 // while game is not complete49 while ( gameStatus == CONTINUE ) // not WON or LOST50 { 51 sumOfDice = rollDice(); // roll dice again52Outlinefig06_11.cpp (2 of 4)Assigning an enumeration constant to gameStatusComparing a variable of an enumeration type to an enumeration constant753 / / determine game status54 if ( sumOfDice == myPoint ) // win by making point55 gameStatus = WON ;56 else57 if ( sumOfDice == 7 ) // lose by rolling 7 before point58 gameStatus = LOST;59 } // end while 6061 // display won or lost message62 if ( gameStatus == WON )63 cout << "P layer wins" << endl;64 else65 cout << "P layer loses " << endl;6667 return 0; // indicates successful termination68 } // end main6970 // roll dice, calculate sum and display results71 int rollDice()72 {73 // pick random die values74 int die1 = 1 + rand() % 6; // first die roll75 int die2 = 1 + rand() % 6; // second die roll76 77 int sum = die1 + die2; // compute sum of die valuesOutlinefig06_11.cpp (3 of 4)Function that performs the task of rolling the dice87879 / / disp lay result s of th is ro l l80 cout << "Player rolled " << die1 << " + " << die281 << " = " << sum << endl;82 return sum; // end function rollDice83 } // end function rollD icePlayer rolled 2 + 5 = 7Player winsPlayer rolled 6 + 6 = 12Player losesPlayer rolled 3 + 3 = 6Point is 6Player rolled 5 + 3 = 8Player rolled 4 + 5 = 9Player rolled 2 + 1 = 3Player rolled 1 + 5 = 6Player winsPlayer rolled 1 + 3 = 4Point is 4Player rolled 4 + 6 = 10Player rolled 2 + 4 = 6Player rolled 6 + 4 = 10Player rolled 2 + 3 = 5Player rolled 2 + 4 = 6Player rolled 1 + 1 = 2Player rolled 4 + 4 = 8Player rolled 4 + 3 = 7Player losesOutlinefig06_11.cpp (4 of 4)9In-Class ExerciseWrite a “Hello World” program.The main function should call a function called “printHello”.printHello should return no value and accept no parameters. Its job is to output the text, “Hello World” and then return control to main()10Good Programming Practice 6.1 Capitalize the first letter of an identifier used as a user-defined type name.11Good Programming Practice 6.2 Use only uppercase letters in the names of enumeration constants. This makes these constants stand out in a program and reminds the programmer that enumeration constants are not variables.12Good Programming Practice 6.3 Using enumerations rather than integer constants can make programs clearer and more maintainable. You can set the value of an enumeration constant once in the enumeration declaration.13Common Programming Error 6.9 Assigning the integer equivalent of an enumeration constant to a variable of the enumeration type is a compilation error.14Common Programming Error 6.10 After an enumeration constant has been defined, attempting to assign another value to the enumeration constant is a compilation error.15Review