PROGRAMMING IN C

1. PROGRAMMING IN C
QUESTIONS WITH ANSWERS
BY,
LAKSHMI.S, M.C.A,M.PHIL.,
ASSISTANT PROFESSOR,
DEPARTMENT OF COMPUTER SCIENCE,
SRI ADI CHUNCHANAGIRI WOMEN’S COLLEGE,
CUMBUM.

2. UNIT I
1. Explain the steps used in program development cycle. *
Program Development Cycle:
• Step by step procedure used to build a computer program.
1. Problem Definition:
• The problem is defined.
2. Requirement Analysis:
• The requirements of the user are analyzed.
3. Program Design:
• The structure of the program is designed.
4. Program Coding:
• Program design is transformed into program code.
5. Testing & Debugging:
• Testing: Program errors are detected.
• Debugging: Program errors are corrected.
6. Documentation:
• Detailed description about the program is written.
7. Maintenance:
• The program is changed in order to correct errors, improve performance and meet user requirements.
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2. Explain the features of a good programming language. *
Features of a Good Programming Language:
1. Simplicity:
Problem Definition
Requirement Analysis
Program Design
Program Coding
Testing & Debugging
Documentation
Maintenance

3. • Simple to learn and use.
2. Naturalness:
• Provide the data types, operators and syntax required to write programs in the specified application area.
3. Abstraction:
• Group essential details and ignore other details.
4. Efficiency:
• Occupy less memory space.
• Fast execution.
5. Structuredness:
• Provide facility to divide a problem into sub-problems and write separate sub-programs for them.
6. Compactness:
• Provide facility to write compact programs.
7. Extensibility:
• Provide facility to extend a program.
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3. Write the algorithm and draw the flowchart to find the product of the first n natural numbers. *
Product of the First n Natural Numbers:
Natural Numbers – 1, 2, 3 . . . n
Algorithm:
Begin
Input n
product  1
for i  1 to n do
Begin
product  product * i;
End
Output product
End

4. Flow Chart:
False
True
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4. Write the algorithm and draw the flowchart to find the factorial of a given number. *
Note: This algorithm and flowchart is same as that of product of first n natural numbers.
Factorial of a Given Number:
n! = 1 * 2 * 3 … * n
Algorithm:
Begin
Input n
fact  1
for i  1 to n do
Begin
fact  fact * i;
End
Output fact
End
Start
Input
n
product = 1
for i = 1 to
n
product = product * i
Output product
End

5. Flow Chart:
False
True
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5. Write the algorithm and draw the flowchart to find the largest of three numbers. *
Largest of Three Numbers:
Algorithm:
Begin
Input a, b, c
if (a > b) then
if (a > c) then
Output a
else
Output c
else
if (b > c) then
Output b
else
Output c
End
Start
Input
n
fact = 1
for i = 1 to
n
fact = fact * i
Output
fact
End

6. Flow Chart:
False True
False True False True
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6. Explain the structure of a C program with an example. *
Structure of a C Program:
• General Structure of a C Program:
Include Section
Global Declaration Section
main()
{
Local Declaration Section
Statement Section
}
User-defined Function Section
• Include Section:
• In this section, header files are included.
• Global Declaration Section:
• In this section, global variables are declared.
• main() Section:
• Execution of the program starts from the main() function.
• Local Declaration Section:
• In this section, local variables used in main() function are declared.
• Statement Section:
• In this section, the C statements required to solve the program are written.
Start
Input a,b,c
End
if (a >
b)?
if (a >
c)?
if (b >
c)?
Output c Output b Output c Output a

7. • User-defined Function Section:
• In this section, user-defined functions are written.
• Example:
• Program to add two numbers.
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7. Explain the steps involved in executing a C program. *
Execution of C Program:
1. Creating the Program:
• The program should be typed in the Turbo C editor and saved.
• This program is called source program.
• Source Program – General Form:
• Example: Sample.c
2. Compiling the Program:
• Compilation is the process of converting the source program into machine language program (object
program).
• The source program should be compiled using the Compile option in the Turbo C editor.
• During compilation, source program is converted into object program.
• Object Program - General Form:
• Example: Sample.obj
3. Linking and Running the Program:
• Linking is the process of connecting header files with the program.
 Include Section
 main() Section
 Local Declaration Section
 Statement Section
filename.c
filename.obj
#include <stdio.h>
main()
{
int a, b, sum;
scanf(“%d %d”, &a, &b);
sum = a + b;
printf(“Sum = %d”, sum);
}

8. • Linking converts object program into executable program.
• Executable Program – General Form:
• Example: Sample.exe
• Executable program should be run using the Run option in the Turbo C editor.
Execution of C Program - Diagram
Source Program
Yes
No
Object Program
Executable Program
Yes
No
Correct Output
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8. Explain the data types in C. *
Basic Data Types:
Data Type Description Size
char Character 1 Byte
int Integer 2 Bytes
float Single-precision floating point number 4 Bytes
double Double-precision floating point number 8 Bytes
Data Type Qualifiers:
Edit Source Program
Compile Source Program
Synta
x
Error
?
Link Object ProgramHeader Files
Run Executable Program
Logic
Error
?
filename.exe

9. • Sign Qualifiers:
1. signed
2. unsigned
• These qualifiers affect the sign of the data type.
• Size Qualifiers:
1. long
2. short
• These qualifiers affect the size of the data type.
• Examples:
• signed int
• unsigned int
• long int
• short int
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9. Explain the formatted input and output functions in detail. ***
Formatted Input Function:
• scanf() function is called Formatted Input Function.
• General Form:
• General Form of control string;: %w data_type
Conversion Character Table:
Data
Type
Conversion
Character
char %c
int %d
float %f
string %s
• Example:
int a;
scanf(“%d”, &a);
Formatted Output Function:
• printf() function is called Formatted Output Function.
• General Form:
• General Form of control string: %w.p data_type
Conversion Character Table:
Data
Type
Conversion
Character
char %c
int %d
float %f
string %s
scanf(“control string”, &variable1, &variable2, … &variable n);
printf(“control string”, variable1, variable2, … variable n);

10. • Printing Integer:
Example:
int x = 2000; Output:
printf(“%d”, x);
• Printing Float:
Example:
float x = 123.4567 Output:
printf(“%8.4f”, x);
• Printing String:
Example:
name = “Kandan”; Output:
printf(“%s”, name);
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10. Explain the unformatted input and output functions in detail. ***
Unformatted Input Functions:
• getchar():
• Used to read a character from the keyboard.
• General Form:
• Example:
char a;
a = getchar();
• gets():
• Used to read a string from the keyboard.
• General Form:
• Example:
char a[10];
gets(a);
Unformatted Output Functions:
• putchar():
• Used to display a character on the monitor.
• General Form:
• Example:
putchar(‘K’);
• puts():
2 0 0 0
1 2 3 . 4 5 6 7
K a n d a n
variablename = getchar();
gets(variablename);
putchar(variablename);

11. • Used to display a string on the monitor.
• General Form:
• Example:
puts(“Kandan”);
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puts(variablename);