## C++ || Snippet – How To Do Simple Math Using Integer Arrays

This page will consist of simple programs which demonstrate the process of doing simple math with numbers that are stored in an integer array.

REQUIRED KNOWLEDGE FOR THIS SNIPPET

```Integer Arrays For Loops Assignment Operators - Simple Math Operations Setw```

Note: In all of the examples on this page, a random number generator was used to place numbers into the array. If you do not know how to obtain data from the user, or if you do not know how to insert data into an array, click here for a demonstration.

The first code snippet will demonstrate how to add numbers together which are stored in an integer array. This example uses the “+=” assignment operator.

``` #1 - Addition Using An Int Array C++ #include <iostream> #include <iomanip> // used for setw #include <ctime> // used for srand & rand using namespace std; // const int allocating space for the array const int NUM_INTS = 12; int main() { // declare variables int arry[NUM_INTS]; // array is initialized using a const variable int totalSum =0; srand(time(NULL)); // place random numbers into the array for(int i = 0; i < NUM_INTS; i++) { arry[i] =rand()%100+1; } cout << "Original array values" << endl; // Display the original array values for(int i = 0; i < NUM_INTS; i++) { cout << setw(4) << arry[i]; } // creates a line seperator cout << "n--------------------------------------------------------"; cout<<"nThe sum of the items in the array is: "; // Find the sum of the values in the array for(int i = 0; i < NUM_INTS; i++) { // the code below literally means // totalSum = totalSum + arry[i] totalSum += arry[i]; } // after the calculations are complete, display the total to the user cout<< totalSum <<endl; return 0; }// http://programmingnotes.org/ 1234567891011121314151617181920212223242526272829303132333435363738394041424344 #include <iostream>#include <iomanip>  // used for setw#include <ctime>   // used for srand & randusing namespace std; // const int allocating space for the arrayconst int NUM_INTS = 12; int main(){     // declare variables     int arry[NUM_INTS]; // array is initialized using a const variable     int totalSum =0;     srand(time(NULL));      // place random numbers into the array     for(int i = 0; i < NUM_INTS; i++)     {          arry[i] =rand()%100+1;     }       cout << "Original array values" << endl;     // Display the original array values     for(int i = 0; i < NUM_INTS; i++)     {          cout << setw(4) << arry[i];     }      // creates a line seperator      cout << "n--------------------------------------------------------";      cout<<"nThe sum of the items in the array is: ";     // Find the sum of the values in the array     for(int i = 0; i < NUM_INTS; i++)     {         // the code below literally means         // totalSum = totalSum + arry[i]         totalSum += arry[i];     }     // after the calculations are complete, display the total to the user     cout<< totalSum <<endl;      return 0;}// http://programmingnotes.org/ ```

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

```Original array values 64 85 44 31 35 2 94 67 12 80 97 10 -------------------------------------------------------- The sum of the items in the array is: 621```

===== SUBTRACTION =====

The second code snippet will demonstrate how to subtract numbers which are stored in an integer array. This example uses the “-=” assignment operator.

``` #2 - Subtraction Using An Int Array C++ #include <iostream> #include <iomanip> // used for setw #include <ctime> // used for srand & rand using namespace std; // const int allocating space for the array const int NUM_INTS = 12; int main() { // declare variables int arry[NUM_INTS]; // array is initialized using a const variable int totalDiffetence =0; srand(time(NULL)); // place random numbers into the array for(int i = 0; i < NUM_INTS; i++) { arry[i] =rand()%100+1; } cout << "Original array values" << endl; // Display the original array values for(int i = 0; i < NUM_INTS; i++) { cout << setw(4) << arry[i]; } // creates a line seperator cout << "n--------------------------------------------------------"; cout<<"nThe difference of the items in the array is: "; // Find the difference of the values in the array for(int i = 0; i < NUM_INTS; i++) { // the code below literally means // totalDiffetence = totalDiffetence - arry[i] totalDiffetence -= arry[i]; } // after the calculations are complete, display the total to the user cout<< totalDiffetence <<endl; return 0; }// http://programmingnotes.org/ 1234567891011121314151617181920212223242526272829303132333435363738394041424344 #include <iostream>#include <iomanip>  // used for setw#include <ctime>   // used for srand & randusing namespace std; // const int allocating space for the arrayconst int NUM_INTS = 12; int main(){     // declare variables     int arry[NUM_INTS]; // array is initialized using a const variable     int totalDiffetence =0;     srand(time(NULL));      // place random numbers into the array     for(int i = 0; i < NUM_INTS; i++)     {          arry[i] =rand()%100+1;     }       cout << "Original array values" << endl;     // Display the original array values     for(int i = 0; i < NUM_INTS; i++)     {          cout << setw(4) << arry[i];     }      // creates a line seperator      cout << "n--------------------------------------------------------";      cout<<"nThe difference of the items in the array is: ";     // Find the difference of the values in the array     for(int i = 0; i < NUM_INTS; i++)     {         // the code below literally means         // totalDiffetence = totalDiffetence - arry[i]         totalDiffetence -= arry[i];     }     // after the calculations are complete, display the total to the user     cout<< totalDiffetence <<endl;      return 0;}// http://programmingnotes.org/ ```

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

```Original array values 10 43 77 10 2 17 87 67 6 95 57 18 -------------------------------------------------------- The difference of the items in the array is: -489```

===== MULTIPLICATION =====

The third code snippet will demonstrate how to multiply numbers which are stored in an integer array. This example uses the “*=” assignment operator.

``` #3 - Multiplication Using An Int Array C++ #include <iostream> #include <iomanip> // used for setw #include <ctime> // used for srand & rand using namespace std; // const int allocating space for the array const int NUM_INTS = 12; int main() { // declare variables int arry[NUM_INTS]; // array is initialized using a const variable int totalProduct =1; srand(time(NULL)); // place random numbers into the array for(int i = 0; i < NUM_INTS; i++) { arry[i] =rand()%100+1; } cout << "Original array values" << endl; // Display the original array values for(int i = 0; i < NUM_INTS; i++) { cout << setw(4) << arry[i]; } // creates a line seperator cout << "n--------------------------------------------------------"; cout<<"nThe product of the items in the array is: "; // Find the product of the values in the array for(int i = 0; i < NUM_INTS; i++) { // the code below literally means // totalProduct = totalProduct * arry[i]; totalProduct *= arry[i]; } // after the calculations are complete, display the total to the user cout<< totalProduct <<endl; return 0; }// http://programmingnotes.org/ 1234567891011121314151617181920212223242526272829303132333435363738394041424344 #include <iostream>#include <iomanip>  // used for setw#include <ctime>   // used for srand & randusing namespace std; // const int allocating space for the arrayconst int NUM_INTS = 12; int main(){     // declare variables     int arry[NUM_INTS]; // array is initialized using a const variable     int totalProduct =1;     srand(time(NULL));      // place random numbers into the array     for(int i = 0; i < NUM_INTS; i++)     {          arry[i] =rand()%100+1;     }       cout << "Original array values" << endl;     // Display the original array values     for(int i = 0; i < NUM_INTS; i++)     {          cout << setw(4) << arry[i];     }      // creates a line seperator      cout << "n--------------------------------------------------------";      cout<<"nThe product of the items in the array is: ";     // Find the product of the values in the array     for(int i = 0; i < NUM_INTS; i++)     {         // the code below literally means         // totalProduct = totalProduct * arry[i];         totalProduct *= arry[i];     }     // after the calculations are complete, display the total to the user     cout<< totalProduct <<endl;      return 0;}// http://programmingnotes.org/ ```

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

```Original array values 33 36 52 28 4 99 97 17 42 81 83 33 -------------------------------------------------------- The product of the items in the array is: 1803759104```

===== DIVISION =====

The fourth code snippet will demonstrate how to divide numbers which are stored in an integer array. This example uses the “/=” assignment operator.

``` #4 - Division Using An Int Array C++ #include <iostream> #include <iomanip> // used for setw #include <ctime> // used for srand & rand using namespace std; // const int allocating space for the array const int NUM_INTS = 12; int main() { // declare variables int arry[NUM_INTS]; // array is initialized using a const variable float totalQuotient =1; // need to save the variable as a float, not an int srand(time(NULL)); // place random numbers into the array for(int i = 0; i < NUM_INTS; i++) { arry[i] =rand()%100+1; } cout << "Original array values" << endl; // Display the original array values for(int i = 0; i < NUM_INTS; i++) { cout << setw(4) << arry[i]; } // creates a line seperator cout << "n--------------------------------------------------------"; cout<<"nThe quotient of the items in the array is: "; // Find the quotient of the values in the array for(int i = 0; i < NUM_INTS; i++) { // the code below literally means // totalQuotient = totalQuotient / arry[i]; totalQuotient /= arry[i]; } // after the calculations are complete, display the total to the user cout<< totalQuotient <<endl; return 0; }// http://programmingnotes.org/ 1234567891011121314151617181920212223242526272829303132333435363738394041424344 #include <iostream>#include <iomanip>  // used for setw#include <ctime>   // used for srand & randusing namespace std; // const int allocating space for the arrayconst int NUM_INTS = 12; int main(){     // declare variables     int arry[NUM_INTS]; // array is initialized using a const variable     float totalQuotient =1; // need to save the variable as a float, not an int     srand(time(NULL));      // place random numbers into the array     for(int i = 0; i < NUM_INTS; i++)     {          arry[i] =rand()%100+1;     }       cout << "Original array values" << endl;     // Display the original array values     for(int i = 0; i < NUM_INTS; i++)     {          cout << setw(4) << arry[i];     }      // creates a line seperator      cout << "n--------------------------------------------------------";      cout<<"nThe quotient of the items in the array is: ";     // Find the quotient of the values in the array     for(int i = 0; i < NUM_INTS; i++)     {         // the code below literally means         // totalQuotient = totalQuotient / arry[i];         totalQuotient /= arry[i];     }     // after the calculations are complete, display the total to the user     cout<< totalQuotient <<endl;      return 0;}// http://programmingnotes.org/ ```

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

SAMPLE OUTPUT

```Original array values 75 38 59 14 53 42 29 88 92 27 69 16 -------------------------------------------------------- The quotient of the items in the array is: 2.72677e-020```