Question

Hello, I need help understanding what happens to the value in each loop. I missed a lot of class so I need help. I decoded the final message but I'm supposed to fill in tables for each function.

Homework 4: Program Trace

Check out this “instructional” video on decoding strings - http://www.youtube.com/watch?v=zdA__2tKoIU

Determine the output of the program below. You will receive no credit for a submission that shows no work. You must make variable tables and show how the values of the variables change as the program executes.

#include <iostream>

#include <string>

using namespace std;

string makeWord(int num [], int total)

{

      string alpha = "abcdefghijklmnopqrstuvwxyz!";

string returnWord = "";

      for (int i = 0; i < total; i++)

            returnWord = returnWord + alpha[num[i]];

           

      return returnWord;

}

void fillArray(int numbers[], int set)

{

       if (set == 0)

       {      numbers[0] = 18;

              numbers[1] = 15;

              numbers[2] = 17;

              numbers[3] = 8;

              numbers[4] = 13;

              numbers[5] = 6;

       }

       else

       {      numbers[0] = 1;

              numbers[1] = numbers[2];

              numbers[2] = 4;

              numbers[3] = 0;           

              numbers[4] = numbers[3] + 10;                  

              numbers[5] = 26;                 

       }

}

int getNum(int& numbers)

{

      int i = numbers * 100 - (10 % 3);

      numbers++;

      return i;

      numbers--;

}

int main()

{

       int numbers[7];

       for (int i = 0; i < 3; i++)

       {

              fillArray(numbers, i);

              cout << makeWord(numbers, 6);

              if (getNum(i) < 0)

                     cout << "\t";

              else

                     cout << "\n";

       }

       system("pause");

}

Variable Table Example

Main function

i loop counter	Numbers	makeWord return value	getNum return value
0
1
2

You will need to provide table examples for the makeWord and fillArray functions.

Answer 1

Here getNum() function before return value will increment value of i . So the for loop inside main function will execute only 2 times, ie when i=0 and when i=2.

When i=0 after get num is called, value of I becomes i=1. Then getNum() returns a -1 to main function

When main function gets a value less than 0 , it will print a “tab”

After that main function for loop will again increment the value and value of I becomes i=2

When getNum() fuction is called gain with i=2; it makes value of i=3 and returns 199

When main function gets a value greater than 0 it will print a “newline”

So the final output:     spring       break!

Where spring and break! are tab separated and a newline character exist after break!