Unit #3-03

Learning Outcome

At the end of this lesson, you will be able to:

• understand and use an if ... then ... else statement

Review

• if ... then statements

Lesson

• watch one way to truly generate random numbers

• go over how to generate a random number in python

  • import random

  • some_variable = random.randint(1, 100) # a number between 1 and 100

    • note that in a flowchart, generating a random number is a process

• go over  If…Then…Else , Computer Based Problem Solving

Activity

• step through the better "Too Many Students" program (see below)

  • notice it now gives an answer no matter what the number is

Daily Assignment

• re-create the "Number Guessing Game" program from before

  • use an If ... Then ... Else, so the user is told if the number is correct or wrong

    • when they get the number wrong, ensure you tell them what the correct number was

  • use the random number generator to generate a new random number every time the program is started over

  • step through your code and see what the random number variable is when testing your program

  • for your test case, you will not know what will happen because of the random numbers

    • instead of having "mathematical" test cases, now you have "scenario" test cases

      • show 1 outcome where the number was guessed correctly

      • show 1 outcome where the number was not guessed correctly

  • in your top-down, flowchart and pseudocode you include a statement for actually generating the random number

  • Note: since you are generating a random number, there is no need for a constants.py file

• read  If…Then…Else , Computer Based Problem Solving

Extra

• recreate the same above program in C

  • in C you will have to explicitly set the seed (hopefully to the clock) or you will always get the same random number

    • https://stackoverflow.com/questions/822323/how-to-generate-a-random-int-in-c 

    • https://www.tutorialspoint.com/c_standard_library/c_function_srand.htm

    • in C

#include <stdlib.h>

#include <stdio.h>

#include <time.h>

int main() {

        // this function allows the user to guess a number

        // and the program decides if the user is correct

        unsigned int seed = time(NULL);

        int randomNumber = rand_r(&seed) % 10;