FUNCTIONS IN C?CLASSIFICATION, PARAMETERS, LOCAL VARIABLE.

 WHAT IS A FUNCTION

                                                                       

function

• A self-contained, named block of code that performs the specific task when called is nothing but a function.

• Note:-functions are the task performers in C projects.

 FUNCTIONS CLASSIFICATION

• We have 2 types of functions they are user-defined functions and library functions.

• A pre-created function that comes with C installation is nothing but a library function, For eg:- print () and scanf().

• Library functions are ready-made named code blocks. We need not create them, Just use them in our programs.

• We can make use of this library function by making the library function available to the program and the next step is calling the library function.

• Our own created function which is the program-created function is nothing but a user-defined function, eg- the main function is the example of a user-defined function.

BENEFITS OF USER-DEFINED FUNCTION

• There are many benefits of user-defined functions, the first one is code reusability which means we can use the code a number of times as when we want in the program writing.

• The second one is modularity is another thing of a user-defined function. Make use of this user-defined function by declaring the function that is the prototype, calling function.

SYNTAX TO DEFINE FUNCTION

• <return type>   <identifier>(parameters)

   {
     <task performing code>
   }

• For eg.

  void add()//function header

{ int a=10; int b=20; int sum=a+b; printf("The sum is %d",sum); }

•  The elements of a function definition function header,body code enclosed between two flower braces are nothing but a function body.

• The function body has 2 parts task performing return statement(optional).

OUTPUT PROGRAMS

//addition1.c
#include<stdio.h>
void add();
main()
{     
}
void add()
{
     int n1,n2,sum;
     printf("Enter the first number:");
     scanf("%d",&n1);
     printf("Enter the second number:");
     scanf("%d",&n2);
     sum=n1+n2;
     printf("The sum of %d and %d is %d",n1,n2,sum);
} 
//addition2.c
#include<stdio.h>
void add();//prototype of the function
main()
{  
    add();//calling the function
}
void add()  //defining the function
{
    int n1,n2,sum;
    n1=20;
    n2=30;
    sum=n1+n2;
    printf("The sum is %d",sum);
 }
//addition2.c
#include<stdio.h>
void add()  //defining the function
{
    int n1,n2,sum;
    n1=20;
    n2=30;
    sum=n1+n2;
    printf("The sum is %d",sum);
 }
main()
{  
    add();//calling the function
}
PARAMETERS OF FUNCTION
Variables declared in the function header while defining a method are known as parameters.
     For eg.
            void add(int a,int b)
           {
	     .....
            }
In the above example, a are parameters, to give input data to the function. I.e. parameters are the means by which data are input to the function for processing.
What is a non-parameterized function: A function that doesn't have parameters is nothing but a non-parameterized function.
ARGUMENTS 
Data items(values) supplied to a function during the function call are nothing but arguments.
In the following add function call, 10 and 20 are arguments.
                   add(10,20);
//addition5.c
#include<stdio.h>
int  add(int a,int b);//function prototype
main()
{
   int sum=add(10,20);//function call
   printf("The sum is %d",sum);
}
int add(int a,int b)
{
   int sum=a+b;//data processing
   return sum;  //processed data returning to the caller 
}
LOCAL VARIABLE
A variable declared inside a function is called a local variable, of one function that is not available to another function.
Variables declared outside the functions (in the global declaration section) are called global variables. Global variables are available to all the functions of the program.
#include<stdio.h>
void add(int ,int );
int subract(int ,int );
int result;//global variable
main()
{
   result=subtract(10,6);
}
void add(int a,int b) // a & b are local variables
{
   result=a+b;
}
int subtract(int n1,int n2) //n1&n2 are local variables
{
     result=n1-n2;
     return result;
}
So in this blog, we talked about functions in c topic and the classification of it then what is parameter, argument, local variable, some of the output programs too.
In the coming blogs we are going to start html blogs in that we are going to cover all the topics.