Store an array from a 2d array in C

Question

I have a 2-d array, we call arr2[3][3]. If I want to store the first row of arr2 to a new array, we call arr1[3], how would I do that?

I tried int arr1[] = arr2[0]. But it doesn't work.

"It doesn't work" isn't a problem statement. Tell us specifically the behavior you're getting. — Robert Harvey
– Robert Harvey, Commented Nov 6, 2013 at 3:36

LeatherFace · Accepted Answer · 2013-11-06 03:33:48Z

2

In C you would have to copy the row of array2 into the array1 using a for loop like so..

for(i=0;i<3;i++)
    arr1[i] =arr2[0][i];

answered Nov 6, 2013 at 3:33

LeatherFace

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PandaRaid · Accepted Answer · 2013-11-06 03:54:23Z

1

You can either assign each element using a loop

for(int i =0; i < 3; i++)
    arr1[i] = arr2[0][i];

Alternatively, you can use memcpy.

memcpy(&arr1[0], &arr2[0][0], sizeof(int) * columnSize);

Make sure that the array being copied to has enough space when doing this approach, otherwise funky stuff will happen (easier to overlook here than with iteration)

edited Nov 6, 2013 at 3:54

answered Nov 6, 2013 at 3:48

PandaRaid

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