Categories of function

These are the four categries of a function.

• A function with argument with return value.
• A function with argument without return value.
• A function without argument with return value.
• A function without argument without return value.

i)A function with argument with return value.

A function which have some argument and return some value.

#include<stdio.h>
int multiply(int x,int y); //prototype define
int  multiply(int x,int y) //called function
{
    int x,y,z;
    z=x+y;
    return z;
}
int main()
{
    int x,y,multi;
    printf("Enter the first value=");
    scanf("%d",&x);
    printf("Enter the second value=");
    scanf("%d",&y);
    multi=multiply(x,y);//calling function
    printf("%d",multi);
    return 0;
}

ii) A function with argument without return value.

A function which have some argument and without return any value.

#include<stdio.h>
void multiply(int x,int y); //prototype define 
void multiply(int x,int y) //called function
{
    int x,y,z;
    z=x*y;
    printf("%d",z);
}
int main()
{
    int x,y;
    printf("Enter the first value=");
    scanf("%d",&x);
    printf("Enter the second value=");
    scanf("%d",&y);
    multiply(x,y);//calling function
    return 0;
}

iii) A function without argument with return value.

A function which have no argument pass and return some value.

#include<stdio.h>
int multiply(void); //prototype define 
int  multiply(void) //called function
{
    int x=10,y=20,z;
    z=x*y;
    return z;
}
int main()
{
    int multi=0;
    multi=multiply();//calling function
    printf("%d",multi);
    return 0;
}

iv) A function without argument without return value.

A function which have no any argument pass and without return any value.

#include<stdio.h>
void multiply(void); //prototype define 
void multiply(void) //called function
{
    int x=10,y=15,z;
    z=x*y;
    printf("%d",z);
}
int main()
{
    multiply();//calling function
	return 0;
}