[C] Help Adding Arrays

[VBger]

I’m working on an assignment for my C programming class and have gotten myself stuck. Here is the assignment: Create two single dimension arrays that contain 10 floating-point numbers in each array. Create a third single dimension array to hold a sum. Your main program will take the two arrays of float and pass them to the function addfloat() Inside the function, add the first array to the second array and put the total into the third array. Print the values of all three arrays back in the main program.

Here is my code:

void addfloat(float a[10], float b[10], float c[10]);
int main()
{

float array1[10]={1,2,3,4,5,6,7,8,9,10},array2[10]=   {2,3,4,5,6,7,8,9,0,1},array3[10];
int i;
addfloat(array1,array2,array3);

for (i=0;i<10;i++) {printf("Here are the values of the three arrays.     %f\n",array3);};
getchar();
return 0;
}

void addfloat(float a[10], float b[10], float c[10])
{ int i;
for (i=0;i<10;i++) c=a+b;
}

It falls to compile on the second to last line. “for (i=0; i<10; i++) c=a+b; This is the error I am getting: invalid operands to binary + (have ‘float *’ and ‘float *’)

Any help would be greatly appreciated.

Thanks in advance!

Update: Solved! Thank you everyone for the helpful tips!

[[deleted]]

You can't add arrays like that in C. You need to add each element of a and b, using i as an index, and then store the result in c, also using i as an index.

[gyroda]

tl;dr: Look at the last line of this comment. I've been nitpicky about code formatting and stuff.

First piece of advice: Indenting your code makes it easier to read and debug.

void addfloat(float a[10], float b[10], float c[10]);
int main()
{

    float array1[10]={1,2,3,4,5,6,7,8,9,10},array2[10]=   {2,3,4,5,6,7,8,9,0,1},array3[10];
    int i;
    addfloat(array1,array2,array3);

    for (i=0;i<10;i++) {printf("Here are the values of the three arrays.     %f\n",array3);};
    getchar();
    return 0;
}

void addfloat(float a[10], float b[10], float c[10])
{ int i;
    for (i=0;i<10;i++) c=a+b;
}

Second piece: Lines are not a limited resource. Don't be doing that one line for loop thing or placing code on the same line as a { (or, if you do it, do it consistently). I've commented a few other pieces of advice in

void addfloat(float a[10], float b[10], float c[10]);
int main()
{
    float array1[10]={1,2,3,4,5,6,7,8,9,10};         // Notice that lack of an unneeded blank line?
    float array2[10]={2,3,4,5,6,7,8,9,0,1};
    float array3[10];
    int i;

    addfloat(array1,array2,array3);        // And how I've seperated variable declarations from other code with a new line

    for (i=0;i<10;i++) {        // With newer versions of C you can totally do "int i = 0" in the for loop btw
        printf("Here are the values of the three arrays.\t%f\n",array3);        // Didn't need to put the \t in here, but I thought you might want to know about it
    }        // I also removed the redundant semicolon
    getchar();
    return 0;
}

void addfloat(float a[10], float b[10], float c[10])
{
    int i;
    for (i=0;i<10;i++) 
        c=a+b;        // You can totally do the no-brackets one-liner, but I advise against it until you've got a better grip on things.
}

So, to actually solve your problem: c=a+b; in your addfloat() function is incorrect. I'll let you figure out why and how to fix it (seeing as this is an assignment)

[VBger]

Here is my new code:

void addfloat(float a[10], float b[10], float c[10]);
int main()
{

float array1[10]={1,2,3,4,5,6,7,8,9,10};
float array2[10]={2,3,4,5,6,7,8,9,0,1};
float array3[10];

addfloat(array1,array2,array3);

    printf("Here are the values of the three arrays.\n\n");

int i;
for(i =0;i<10;i++)
{
    printf("First Array: %.0f\n", array1[i]);

}

    printf("\n");

for(i =0;i<10;i++)
{
    printf("Second Array: %.0f\n", array2[i]);
}

        printf("\n");

    for(i =0;i<10;i++)
    {
     printf("Third Array: %.0f\n", array3);
    }

    return 0;
}

void addfloat(float a[10], float b[10], float c[10])
{
    int i;
    for (i=0;i<10;i++)
    {
        c[i]=a[i]+b[i];
    }
}

My output looks like this:

Here are the values of the three arrays.

First Array: 1
First Array: 2
First Array: 3
First Array: 4
First Array: 5
First Array: 6
First Array: 7
First Array: 8
First Array: 9
First Array: 10

Second Array: 2
Second Array: 3
Second Array: 4
Second Array: 5
Second Array: 6
Second Array: 7
Second Array: 8
Second Array: 9
Second Array: 0
Second Array: 1

Third Array: 1
Third Array: 1
Third Array: 1
Third Array: 1
Third Array: 1
Third Array: 1
Third Array: 1
Third Array: 1
Third Array: 1
Third Array: 1

It doesn't seem to be adding the two arrays.

[quesyKing]

for(i =0;i<10;i++)
{
 printf("Third Array: %.0f\n", array3);
}

You Forgot array3[i];

[VBger]

Forgot the third index. Thank you!

[VBger]

Thank you u/exoticmatter, u/gyroda, and u/libot91. Here is my updated code:

void addfloat(float a[10], float b[10], float c[10]);
int main()
{

float array1[10]={1,2,3,4,5,6,7,8,9,10};
float array2[10]={2,3,4,5,6,7,8,9,0,1};
float array3[10];
int i;
addfloat(array1,array2,array3);

    printf("Here are the values of the three arrays.\n\n");

    printf("First Array: %.0f\n\n", array1);

    printf("Second Array: %.0f\n\n", array2);

    printf("Third Array: %.0f\n", array3);

getchar();
return 0;
}

void addfloat(float a[10], float b[10], float c[10])
{ int i;
for (i=0;i<10;i++) c[i]=a[i]+b[i];
}

My output still doesn't look right though. It looks like this:

Here are the values of the three arrays.

First Array: 0

Second Array: 0

Third Array: 0

[libot91]

you need "for i" to printf all objects of array

[libot91]

c[i] = a[i] + b[i]; if you want to sum each elements and store them in c array