Function is a block of code which performs a specific task . function is a process .
There are main two types of functions in c
- System defined function : These types of functions are pre-defined functions . The functions which are already defined by system and user can not change them these functions called as system defined functions . e.g void main()
- User defined functions : These functions are defined by user . It has main four types which are explained below .
- Function with arguments and with return value
- Function without arguments and without return value
- Function with arguments but no return value
- Function without arguments but with return value
Parts of user defined function
- function declaration or prototype
- function calling
- function definition
Let's solve with the help of diagram,
Syntax :
data_type function_name(parameter/arguments)int fun(int x, int y)
Let's explain it ,
1.Function with arguments and with return value:
Here we will pass the arguments and return value as well.Example :Q. Write c program for sum of two numbers using function
#include<stdio.h>#include<conio.h>int sum(int p,int q);void main(){int x,y,z;printf("Enter value for x : ");scanf("%d",&x);printf("Enter value for y : ");scanf("%d",&y);z=sum(x,y);printf("Sum =%d",z);getch();}int sum(int p,int q){int z;z=p+q;return z;}
2. Function without arguments and without return value
This will be the function without arguments and without any return valueExample :
Q. Write C program that uses no arguments and no return value
#include<stdio.h>#include<conio.h>void list(void);void main(){int choice;menus();printf("Enter your choice : ");scanf("%d",&choice);getch();}void menus(void){printf("1.Ishita\n");printf("2.Amar\n");printf("3.Bhavana\n");printf("4.Jogi\n");}