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#include<iostream>
using namespace std;
int main()
{   
    // declared and initialized the 2d array
    int arr2d[3][4] = {{1,2,3,4}, {5,6,7,8}, {9,10,11,12}};
    int i, j;
    system("cls");
    for (i = 0; i < 3; i++)
    {
        for (j = 0; j < 4; j++)
        {
            cout << arr2d[i][j] << "\t";
        }    
        cout << endl;
    }
    system("pause");      
 }

This is my (professor's) code. I'm still a newbie to C++ tho (1st year student in college actually). I want to know a simple and really basic code that will help me to get the sum of all the values I declared and initialized in the 2D array. :)

*BTW I'm using Dev Bloodshed C++ 4.9.9.2

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2 Answers 2

Reset to default
1

Create a integer to contain the sum. Then, inserted after you cout the value:

sum+=arr2d[i][j];

This simply keeps a running total of all the values. When your loops finish, it will have encountered and added every value to itself.

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1 Comment

Thank you so much! I can't 1+ up your answer though, I need more rep. Haha, thanks a bunch man :)
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You can use the std::accumulate free function (found in the header <algorithm>):

int arr2d[3][4] = {{1,2,3,4}, {5,6,7,8}, {9,10,11,12}};
int sum = std::accumulate(&arr2d[0][0], &arr2d[2][4], 0);

The &arr2d[0][0] is the pointer to the beginning of the array (which act like a random access iterator for the algorithm) and the &arr2d[2][4] is the address of the past-the-end element of the array (which is required by the function). Notice that the past-the-end element is guaranteed by the Standard to exist and have a valid address.

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