The document discusses functions in C programming, including the implementation of a function to calculate the maximum of two integers and another for computing the factorial of a number. It provides code snippets illustrating how to use function prototypes and passes arguments, along with examples for reading user input and outputting results. Additionally, it highlights some issues in the code, such as incorrect variable names and nested function definitions.

1. Functions in C Language

2. main()

3. main()

4. main()

5. main()

6. main()x
y
x is actual argument
y is formal argument

7. y
x 5
5

8. voidintfloat

12. #include<stdio.h>
#include<conio.h>
int maxint(int,int); // prototype of the function
int main()
{
int x, y;
int max;
clrscr();
printf(“Enter 2 numbersn”);
scanf(“%d%d”,&x,&qy);
max = maxint(x,y); // function call
printf(“Largest number is %dn”,max);
getch();
}
int maxint(int p, int q)
{
if(p>q)
return p;
else
return q;
}

14. #include<stdio.h>
#include<conio.h>
int maxint(int,int); // prototype of the function
int main()
{
int x, y;
int max;
clrscr();
printf(“Enter 2 numbersn”);
scanf(“%d%d”,&x,&q);
int maxint(int x, int x)
{
if(x>y)
return x;
else
return y;
}
getch();
}
One function block inside other
function block

15. #include<stdio.h>
#include<conio.h>
int maxint(int,int); // prototype of the function
int main()
{
int x, y;
int max;
clrscr();
printf(“Enter 2 numbersn”);
scanf(“%d%d”,&x,&qy);
max = maxint(x,y); // function call
printf(“Largest number is %dn”,max);
getch();
}
int maxint(int p, int q)
{
if(p>q)
return p;
else
return q;
}

16. #include<stdio.h>
#include<conio.h>
int maxint(int,int); // prototype of the function
int main()
{
int x, y;
int max;
clrscr();
printf(“Enter 2 numbersn”);
scanf(“%d%d”,&x,&qy);
max = maxint(x,y); // function call
printf(“Largest number is %dn”,max);
getch();
}
int maxint(int p, int q)
{
if(p>q)
return (p);
else
return q;
}

17. Factorial value
n! = n * n-1 * n-2 * n-3 * n-4……..
5! = 5 * 4 * 3 * 2 * 1
5! = 120

18. #include<stdio.h>
#include<conio.h>
void main()
{
int number;
int fact;
clrscr();
printf(“Enter Numbert”);
scanf(“%d”,&number);
fact = factorial(number);
printf(“%d! = %dn”,number,fact);
getch();
}
int factorial(int x)
{
int i;
int f = 1;
for(i=x; i >= 1; i--)
{
f = f * i;
}
return f;
}
Return type Formal argument
5! = 5 * 4 * 3 * 2 * 1
5 1
x