C Programming - Declarations and Initializations - Discussion

Prototype means we specifies the interface of that declared function. And we will use that function for coherent task.

#include<stdio.h>
int funcall(int,int);//function prototyping
void main()
{
int sum=0;
int a=10,b=30;
sum=funcall(a,b);
printf("\nsum is %d",sum);
}

int funcall(a,b) //function definition
{
int cal=a+b;
printf("\ncal=%d",cal);
return cal;
}

out put: 40


Sorry prathyusha ur output is wrong that is not 10, 30 is the anws.
We have not to declare a is must that is mandetory...
y b'case we already declaring function call dat is funcall(int,int)..
any how ur explaination is good...

Thank u mr.sundar

What is the difference between initializing and declaring?

Hi tomson,
Declaration is
int a;
char b;
float c;
.....
Initialization is
a=10;
b='h';
c=1.2;

We can use both declaration and initialization at same time
int a=10;
char b='w';
......
I think so now u understand.
If you hav any other doubt ask me.

What about initializing and defining. ?

What is difference between definition and declaration?

Declaration is the process of declaring the variable with some special name and its data-type,scope,memory storage etc. and definition is actually assining some value to that variable.

In case of function declaration is defining its prototype and declaration is code where we specify what the function actually does.

Examples:

case 1) variable

Variable Declaration:
int a,b[10];

Variable Definition:
a=1, b={1,2,3,....};


Function Declaration:
void display();

Function Definition:

void display()
{
printf("......");
}

What is the calling function?

A function call is an expression containing a simple type name and a parenthesized argument list.

What is the difference between prototyping and declaration ?