Functions

Functions:

A function is itself a block of code which can solve simple or complex task/calculations. A function performs calculations on the data provided to it is called "parameter" or "argument". A function always returns single value result. 

Types of function:

 1. Built in functions(Library functions)

 a.) Inputting Functions.

 b.) Outputting functions. 

2. User defined functions. 

a.) fact();

 b.) sum();

 Parts of a function: 

1. Function declaration/Prototype/Syntax. 

2. Function Calling. 

3. Function Definition.

 

1.)Function Declaration:

 Syntax: <return type><function name>(<type of argument>)

The declaration of function name, its argument and return type is called function declaration.

 2.) Function Calling:

 The process of calling a function for processing is called function calling.

 Syntax: <var_name>=<function name>(<list of arguments>)

3.) Function defination:

The process of writing a code for performing any specific task is called function defination.

 Syntax: 

<return type><function name>(<type of argument>)

{ 

<statement 1>

<statement 2>

return(<value>) 

}

 Example: program based upon function: 

WAP to compute cube of a no. using function.

#include<stdio.h>

#include<conio.h>

void main() 

{ 

int c,n;

 int cube(int);

 printf("Enter a no.");

scanf("%d",&n);

 c=cube(n); 

printf("cube of a no. is=%d",c);

}

 int cube(int n)

 {

 c=n*n*n; 

return(c);

 } 

Recursion 

Firstly, what is nested function? 

When a function invokes another function then it is called nested function.

 But, 

When a function invokes itself then it is called recursion.

 NOTE: In recursion, we must include a terminating condition so that it won't execute to infinite time.

Example:

 program based upon recursion:

 WAP to compute factorial of a no. using Recursion:

 #include

#include

void main() 

{

 int n,f;

 int fact(int)

 printf("Enter a no.");

scanf("%d",&n);

 f=fact(n); 

printf("The factorial of a no. is:=%d",f);

}

 int fact(int n)

 int f=1; 

{ 

if(n=0) 

return(f);

 else

 return(n*fact(n-1));

 }