Passing two arguments - c

Question

I want to pass two arguments into void Dividing from void Assign_numbers and void Maximum. I have only learnt to pass one argument at a time. Can you please tell me what I have to do print out the following variables inside void Dividing. If it's possible, I don't want the format of my code to change drastically. Can you also show me an example, since I am a visual learner. Thanks
#include <stdlib.h>
#include <stdio.h>
#define Max 6
struct Numbers
{
double a,b,c,d,e,f;
};
void Maximum(double *ptr);
void Dividing(double Maximum, double *ptr);
void Assign_numbers()
{
struct Numbers number;
number.a=45.78;
number.b=81.45;
number.c=56.69;
number.d=34.58;
number.e=23.57;
number.f=78.35;
Maximum((double*) &number);
Dividing((double*) &number);
}
void Maximum(double *ptr)
{
int i=0;
double Maximum = ptr[0];
for(i;i<Max;i++)
{
if(ptr[i]> Maximum)
{
Maximum = ptr[i];
}
}
Dividing(Maximum);
}
void Dividing(double Maximum, double *ptr)
{
printf("%.2f", Maximum);
printf("%.2f",ptr[3]);
}
int main()
{
Assign_numbers();
return 0;
}

Answer 1

Use array instead of struct - shwon here with reference example
Like Joachim Pileborg said. Don't use a struct as an array. In your case use a multidimensional array.
double[10][6] numbers;
You can easily iterate through such an array like so:
#include <stdio.h>
int main () {
/* an array with 2 rows and 6 columns*/
double numbers[2][6] = {
{45.78, 81.45, 56.69, 34.58, 23.57, 78.35},
{1,2,3,4,5, 6}
};
int i, j;
/* output each array element's value */
for ( i = 0; i < 2; i++ ) {
for ( j = 0; j < 6; j++ ) {
printf("numbers[%d][%d] = %f\n", i,j, numbers[i][j] );
}
}
/* Output by reference */
for(i = 0; i < 2; i++){
for(j=0; j < 6; j++ ){
printf("numbers[%d][%d] = %f\n", i, j,*(*(numbers + i) + j));
}
}
return 0;
}
Why the current code fails
Now onto explaining how your code (does not) work and a little about how pointers work. First off:
Dividing(double Maximum, double* ptr);
Does not work in the way you think it does. "double Maximum" is a new double variable that works within the scope of Dividing and is not a variable retrieved from the function:
void Maximum(double *ptr);
If you already knew this, then you should know or at least have expected how poor the naming of your variables are(keep it lowerCamelCase).
Now lets get onto what you're trying to do. IMHO your code is completely broken unless I am noticeing something. In Assign_numbers() you want to call Dividing() using a pointer reference. In Maximum() you want to call Dividing() again, but this time sending only a value. It doesn't make it better that you have 2 separate different calls that each have one parameter. But the function has to have two parameters. Now in order to iterate through the variables in a struct - again this is not recommended and the bottom code only serves as an example.
struct Numbers
{
double a,b,c,d,e,f;
};
struct Numbers Assign_numbers()
{
struct Numbers number;
number.a=45.78;
number.b=81.45;
number.c=56.69;
number.d=34.58;
number.e=23.57;
number.f=78.35;
return number;
}
int main()
{
struct Numbers number;
number = Assign_numbers(number);
double *value = &(number.a); //take address of the first element, since a pointer always counts upwards.
int i;
/*This loops through the addresses of the struct starting from the initial address in number.a and moves upwards 5 times and hopefully ends in number.f. Seriously bad way to construct arrays*/
/*Just try replacing sizeof(number) with sizeof(double). suddenly you get all kinds of weird values because you have ended up outside of the struct*/
/*Also note that this only works when all the datatypes in the struct have a size of 8 bytes(the size of double) */
for (i = 0; i < sizeof(number) / sizeof(double); i++){
printf("[%d]: %f\n",i, value[i]);
}
return 0;
}
New working code
With all that said. This is the closest I am going to to be able to make your code work since I have no idea what you're trying to accomplish:
#include <stdlib.h>
#include <stdio.h>
#define Max 6
struct Numbers
{
double a,b,c,d,e,f;
};
void Maximum(double *ptr);
void Dividing(double *ptr);
void Assign_numbers()
{
struct Numbers number;
number.a=45.78;
number.b=81.45;
number.c=56.69;
number.d=34.58;
number.e=23.57;
number.f=78.35;
Maximum(&number.a); //You need to parse the very first address of the struct. IN this case 'a'
Dividing(&number.a);
}
void Maximum(double *ptr)
{
int i=0;
double maximum = ptr[0];
for(i;i<Max;i++)
{
if(ptr[i]> maximum)
{
maximum = ptr[i];
}
}
printf("maximum: %f", maximum);
}
/*//removed the first parameter since it was not clear what it was for and you only had function calls to this function with one parameter */
void Dividing(double *ptr)
{
printf("%.2f",ptr[3]);
}
int main()
{
Assign_numbers();
return 0;
}