8/12/2019 M04_UN08_P01

1/22

Unit 4.8 - Function

Presentation1

Programming Concepts and Constructs

(C Language)

8/12/2019 M04_UN08_P01

2/22

Revision

1. Two-dimensional arrays are initialised

__________________.

a. Row-wise.b. Column-wise.

2. In x[i][j], i refers to ______________ and jrefers to __________________.

8/12/2019 M04_UN08_P01

3/22

Objectives

At the end of this presentation, you will be able to:

List the advantages of functions

List the function components

List the types of functions

Accept data from the user and display data on

the screen using standard input/output functions

8/12/2019 M04_UN08_P01

4/22

Functions

Is a block of statements that performs a

specific task.

8/12/2019 M04_UN08_P01

5/22

Advantages of Using Function

Reusability

Function Portability

Modularity

Easy to Debug

Easy to Modify and Extend

8/12/2019 M04_UN08_P01

6/22

Function Components

Function Header - Specifies the function

name along with parameters.

Function Body- Contains the actual code ofthe function.

Return Statement- Returns a value to the

main program.

8/12/2019 M04_UN08_P01

7/22

Types of Function

The two types of functions in C language are:

Built-in functions

User-defined functions

8/12/2019 M04_UN08_P01

8/22

Built-in Functions

Are pre-defined functions that are part of theC language.

Built-in functions are also called as libraryfunctions.

Example

printf()

scanf()

8/12/2019 M04_UN08_P01

9/22

Built-in Functions

The code for these functions are already

defined by the C language.

To use a particular function, you must includethe respective header file.

8/12/2019 M04_UN08_P01

10/22

User-Defined Functions

Are the functions written by the users for

performing a specific task.

Example

main()

8/12/2019 M04_UN08_P01

11/22

Header File - stdio.h

This is the standard input-output header file.

The functions in this header file are used for

accepting the input data from the user anddisplaying the processed data on the screen.

8/12/2019 M04_UN08_P01

12/22

Functions in stdio.h

Function : getchar()

Description : Accepts a single character from

the user.

Syntax : getchar();

8/12/2019 M04_UN08_P01

13/22

Functions in stdio.h

Function : putchar()

Description : Displays a single character on

the screen.

Syntax : putchar();

8/12/2019 M04_UN08_P01

14/22

Hands-On!

ProgramD8_1.Cwill accept and display acharacter on the screen.

8/12/2019 M04_UN08_P01

15/22

8/12/2019 M04_UN08_P01

16/22

Functions in stdio.h

Function :puts()

Description :Displays the string on the

screen.

Syntax : puts();

8/12/2019 M04_UN08_P01

17/22

8/12/2019 M04_UN08_P01

18/22

Summary

In this presentation, you learnt the following:

A function is a block of statements that performs

a specific task.

Function components:

Function Header Function Body

Return Statement

8/12/2019 M04_UN08_P01

19/22

Summary

Types of functions available in C are: Built-in functions

User-defined functions

Built-in functions are pre-defined functionsthat are part of the C language.

Standardinput-output functions can be usedto accept input from the user and display thesame.

8/12/2019 M04_UN08_P01

20/22

Assignment

1. What are the two types of functionsavailable in C language?

2. Which of the following functions is moreappropriate for reading multi-word strings?

a) getchar()

b) putchar()

c) gets()

d) puts()

8/12/2019 M04_UN08_P01

21/22

Lab Exercise

1. Write a program to accept characters from

the user. The program must accept the

characters till the user presses the Enterkey.

8/12/2019 M04_UN08_P01

22/22

Lab Exercise

2. Write a program to count the number of

blank spaces in the input string.