The document presents an overview of functions in C programming, including function definition, declaration, arguments, and return values. It emphasizes the importance of functions for task execution and demonstrates how to declare and use functions with an example program that adds two numbers. Additionally, it mentions built-in functions from the C standard library to avoid code duplication.

1. C PROGRAM
PRESENTATION
GGS INDRAPRASTHUNIVERSITY
Submitted to Submitted
by
Ms. Madhu Chauhan Manish
Assistant Professor 048
BCA E1 2016-2019

2. Topic
 Function-Definition, Need, Declaration,
Definition, Arguments, Return Value.

3. Function-Definition
 A function is a group of statements that together
perform a task. Every C program has at least
one function, which is main(), and all the most
trivial programs can define additional functions.
 A function declaration tells the compiler about a
function's name, return type, and parameters.

4. Need
 The C standard library provides numerous built-in
functions that your program can call. For
example, strcat() to concatenate two
strings, memcpy() to copy one memory location
to another location, and many more functions.
 No Need to copy code just call by its function
name

5. Function Declarations

6. Function Arguments
 In programming, argument refers to the
variable passed to the function.
 Parameters a and b accepts the passed
arguments in the function definition. These
arguments are called formal parameters of the
function.

7. Example of an Argument

8. Syntax
#include<stdio.h>
#include<conio.h>
return_type function_name (parameter list);
{
local declaration;
Statements;
return statement;
}

9. Return Value
 The return statement terminates the execution of a
function and returns a value to the calling function.

10. Example
 Program to add two numbers with arguments and return value
#include<stdio.h>
#include<conio.h> //headers
Int sq(int num) //return type function name and argument
{
int ans;
ans=num*num; //statement
return(ans); //returning value of ans
}
void main()
printf(“Enter the number”);
scanf(“%d”,&num);
result=sq(num); //value of above program
printf(“%d”,result);
}

11. Thank you