Lecture21 categoriesof userdefinedfunctions.ppt

*

Categories of User Defined Functions in ‘C’

Prakash KhaireLecturer, B V Patel Inst. of BMC & IT, Gopal

Vidyanagar

Prakash Khaire, Lecturer

B V Patel Inst. Of BMC & IT, Gopal Vidyanagar

*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion

Introduction● Functions are categorized based on the arguments are

passed or whether a value is returned or not

●Functions with no agruments and no return values.●Functions with arguments and no return values.●Functions with arguments and one return value.●Functions with no arguments but return a vlues.●Functions that return multiple values

Prakash Khaire, Lecturer B V Patel Inst. Of BMC & IT, Gopal VidyanagarPrakash Khaire, Lecturer B V Patel Inst. Of BMC & IT, Gopal Vidyanagar

*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion

Functions with no arguments and no return values

●You do not pass data to the called function.●function with no return type does not pass back data to the calling function.●This type of function which does not return any value cannot be used in an expression it can be used only as independent statement.


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion


#include<stdio.h> #include<conio.h> void printline(){ int i; printf("\n"); for(i=0;i<30;i++) { printf("-"); } printf("\n"); }

Prakash Khaire, Lecturer B V Patel Inst. Of BMC & IT, Gopal Vidyanagar

void main() { clrscr(); printf("Welcome to function in C"); printline(); printf("Function easy to learn."); printline(); getch(); }


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion



*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion

Functions with arguments and no return value

●It accept data from calling function.●you send data to the called function from calling function but you cannot send result data back to the calling function.


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion


#include<stdio.h> #include<conio.h> void add(int x, int y) { int result; result = x+y; printf("Sum of %d and %d is %d.\n\n",x,y,result); }


void main() { clrscr(); add(30,15); add(63,49); add(952,321); getch(); }


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion



*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion

Functions with arguments and return value

●It can send arguments (data) from the calling function to the called function●It wait for the result to be returned back from the called function back to the calling function●This type of function is mostly used in programming world because it can do two way communications●It can accept data as arguments as well as can send back data as return value●The data returned by the function can be used later in our program for further calculations.


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion


#include<stdio.h> #include<conio.h> int add(int x, int y) { int result; result = x+y; return(result); }


void main() { int z; clrscr(); z = add(952,321); printf("Result %d.\n\n",add(30,55)); printf("Result %d.\n\n",z); getch(); }


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion



*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion

Functions with no arguments but returns value

●A function which does not take any argument but only returns values to the calling function.●The best example of this type of function is “getchar()” library function which is declared in the header file “stdio.h”.


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion


#include<stdio.h> #include<conio.h> int send() { int no1; printf("Enter a no : "); scanf("%d",&no1); return(no1); }


void main() { int z; clrscr(); z = send(); printf("\nYou entered : %d.", z); getch(); }


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion



*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion

Functions that return multiple values

●To send values to the called function, in the same way we can also use arguments to send back information to the calling function●The arguments that are used to send back data are called Output Parameters.


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion

Functions that return multiple values

#include<stdio.h> #include<conio.h> void calc(int x, int y, int *add, int *sub) { *add = x+y; *sub = x-y; }


void main() { int a=20, b=11, p,q; clrscr(); calc(a,b,&p,&q); printf("Sum = %d, Sub = %d",p,q); getch(); }


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion

Recursion


●A function calling itself again and again to compute a value●Normally function are called by main function or by some another function●But in recursion the same function is called by itself repeatedly


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion

Closingint fact(int k) 1st call -> return(4 * fact(4-1));{ return(4 * fact(3));

if(k==0) 2nd call -> return(3 * fact(3-1));{ return(3 * fact(2));

return(1); 3rd call -> return(2 * fact(2-1));} return(2 * fact(1));else{

return(k * fact(k-1));}

}


*

Category 1

Category 2

Category 3

Introduction

Category 4

Category 5

Recursion

Use of Recursive Function


●Recursive functions are written with less number of statements compared functions●Recursion is effective where terms are generated successively to compute a value


Date post:	22-Nov-2014
Category:	Technology
Upload:	eshikshak
View:	1,731 times
Download:	3 times

Lecture21 categoriesof userdefinedfunctions.ppt

Technology