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# summing up an array

I need to create a function that sums up a 2x7 array.  Can someone help?
0
nationnon
• 6
• 5
1 Solution

Commented:
int sum = 0;
int array [2][7];

for (int i = 0; i<2;i++)
{
for (int j = 0; j<7; j++)
{
sum = array[i][j];
}
}
0

Author Commented:
Adjusted points from 25 to 50
0

Author Commented:
can you look at this and see what i'm doing wrong?

#include <iostream.h>
#include <fstream.h>

int sum = 0;
int array [2][7];

int sum()
{
for (int i = 0; x<2;x++)
{
for (int j = 0; y<7; j++)
{
sum = array[i][j];
}
}

}

int smallArray()
{
int smallest=array[0];
for(int x=1;x<array_size;x++)
{if (smallest>array[x])smallest=array[x];}
cout<<smallest;
}

void main()

//Declare and initialize array
{
int num[2][7] = {0,0};

int hold[2][7];

for (int x =0; x < 2; ++x)
{
for (int y = 0; y < 7; ++y)
{
cout << "Press a whole number then hit enter ";
cin  >> hold [x][y];
}
}

}

// Biggest array function
{
int bigArray()

int biggest=array[0];
for(int x=1;x<array_size;x++)
{if (biggest<array[x])biggest=array[x];}
cout<<biggest;

cout << "Choose 1 for biggest number ";
cout << "Choose 2 for smallest number ";
cout << "Choose 3 for the sum of all numbers in array ";

cout << bigArray() << endl;
cout <<  endl;

cout << smallArray() << endl;
cout << endl;

cout << sumArray() <<endl;
cout << endl;
}
int smallArray()
{
int smallest=array[0];
for(int x=1;x<array_size;x++)
{if (smallest>array[x])smallest=array[x];}
cout<<smallest;
}
0

Commented:
I made a slight mistake in the code I sent you and I just caught it in mine and in yours.
int sum = 0;
int array [2][7];

for (int i = 0; i<2;i++)
{
for (int j = 0; j<7; j++)
{
sum += array[i][j];
}
}

You, (we) cannot just say:
sum = array[i][j]
because then we are just reassigning sum the value in the array at the values of i and j and will ultimately just end up with sum = the value at array[2][7] since that will be the last  number that goes through.  We have to increment sum each time through the for loop to add the values you want,
sum = array[0][0]+array[0][1]+array[0][2].....+ array[2][6] + array[2][7]

Try fixing your sum function to the above and let me know how it works.

0

Author Commented:
I'm still getting errors
0

Author Commented:
I got one error

-------------------------

missing function header (old-style formal list?)

and it points to the first bracket.
0

Commented:
please send me the code you have as of now.
0

Commented:
You are making this program much more difficult then it needs to be.  I would suggest starting over as painful as that sounds.  You need to unit test as you go.  For example, first write a program that reads in a 2X7 array and output it to make sure that part works, then try summing the array, once that is tested then try to find the largest integer and so on.  It looks like you wrote all of the code in one lump...that is NEVER a good idea when you program, it makes tasks like debugging very difficult because you cannot eliminate any one area.  Does this make sense?
0

Commented:
Here is the function definition for your sum array:

// declaration
int sumarray(int array[][]);

// definition
int sumarray (array[][])
{
for (int i = 0; i<2;i++)
{
for (int j = 0; j<7; j++)
{
sum = sum + array[i][j];
}
}
}

You have to pass in an array, you thus it has to be in the declaration and the definition.  This is the full explanation of how to sum a 2X7 array.

0

Commented:
I'm feeling generous, to fix this function

/* declaration; void since you are coutint the value you are not actually passing it */

void smallArray(array[2][7]);

// define the function:

void smallArray(array[][])
{
// give smallest some huge number
int smallest =100000000;
// loop through the array to search
for(int x=0; x<2; x++)
{
for (int y = 0; y< 7; y++)
{
if (smallest < array[x][y])
smallest=array[x][y];
}
}
// to output value to screen
cout <<  smallest;

/* to return the value out of the function- need to make the void an integer if you do this*/
return smallest;
}

0

Author Commented:
yes, and you're right
0
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