Looping:
The process of executing the same
statement repeatedly until a condition is satisfied is called looping. Every
loop has three fundamental components: initialization, condition and counter.
An initialization statement defines the starting point of the loop. The
condition defines the stopping point of the loop and finally the counter counts
the number of iterations. The increment and decrement operations are used as
counter.
If the task or set of instructions
required to be executed “n” number of times, we can use loop statements.
In C- language we have 3 types of
looping structures.
1.
For
loop
2.
While
loop
3.
Do-while
loop
1.
For Loop
The for loop is applied in the situation
when you exactly know how many times you want to execute the statements. It is entry-controlled loop.
Syntax of for loop:
for (initialization; condition;
increment/decrement)
{
body
of loop
}
Example of FOR Loop:
// Program to display
“I am a student of class 12.” 10 times using for loop
#include<stdio.h>
#include<conio.h>
void
main()
{
int
i;
for
(i=1;i<=10;i++)
{
printf
("I am a student of class 12.\n");
}
getch();
}
2.
While Loop
The while
loop executes a statement or a black of statements as long as a condition
evaluates to true. The while loop is mainly used in situations where you don’t
know in advance how many times the loop will be executed. The loop terminates
when the condition evaluates to false.
Syntax
of while loop
Initialization;
while (condition)
{
Statements
……………………….
Increment/decrement
}
The while loop must initialize variable before the
loop begin. The condition consists inside while parenthesis. The increment/decrement
performed inside the body of loop i.e., within braces.
Example
of While -Loop:
//program
to display " I am a student of class 12" 10 times using while loop
#include<stdio.h>
#include<conio.h>
void main()
{
int i=1;
while(i<=10)
{
printf("I
am a student of class 12.\n");
i++;
}
getch();
}
3.
do-while loop
The working of do-while
loop is identical to that the while loop, except that in the do-while loop, a
condition is checked at the end of the loops after each iteration. It means
that the do-while loop definitely executes at least once even if the condition
is false. Unlike the while loop, a semicolon has to be placed after while
expression in the do-while loop; otherwise, the loop will not execute.
Syntax
of do-while loop:
initialization;
do
{
Statements;
Increment/decrement;
}
while condition ( );
#
Differences between while and do-while loop:
While
loop
|
do-while
loop
|
1.
Condition is evaluated before the statement is executed.
|
1.
Condition is evaluated after the statement is executed.
|
2.
It is an entry control loop.
|
2.
It is an exit control loop.
|
3.
It has a keyword While.
|
3.
It has two keyword do and while.
|
4.
Semicolon is not placed after the while condition.
|
4.
Semicolon is placed after the while condition.
|
5.
It does not execute a statement when the condition is false.
|
5.
It executes statement once even the condition is false.
|
6.
Example:
//program to display
" I am a student of class 12" 10 times using while loop
#include<stdio.h>
#include<conio.h>
void
main()
{
int
i=1;
while(i<=10)
{
printf("I
am a student of class 12.");
i++;
}
getch();
}
|
6.
Example:
//program to display
" I am a student of class 12" 10 times using do-while loop
#include<stdio.h>
#include<conio.h>
void
main()
{
int
i=1;
do
{
printf("I
am a student of class 12.");
i++;
}while(i<=10);
getch
();
}
|
Infinite loop
The
loops that do not end are called infinite loop. Generally, infinite loops are
used in server code where the servers have to run without any interruption.
//program
to show infinite loop
#include<stdio.h>
#include<conio.h>
void
main()
{
clrscr();
int
i;
for(i=1;i>=0;i++)
{
printf("%d",i);
}
getch();
}
Jumping Statement:
Jumping
statements are particularly used to jump execution of program statements from
one place to another place inside a program. These statements may executes same
program statement repeatedly or skip some program statements. Following are the
jumping statements used in C.
·
break
·
continue
·
goto
Break and
continue statement:
1. Break statement:
The break statement is used to exit from
a while, for, do-while or switch structures. It can only be used inside the
body of a for, while, do-while, or switch statement.
2.
Continue Statement:
The continuous causes the loop to be
conditioned with the next iteration after skipping any statements in between.
The continue statements tells the compiler “skip the following statements and
continue with the next iteration”.
# Differentiate between Break and
Continue Statement
Break
Statement
|
Continue
Statement
|
1.
The break statement is used to terminate the control from the switch-case and
loop structure.
|
1.
The continue statement is used to by-pass the execution of the further
statements.
|
2.
When break statement encountered the entire loop or switch statement is
terminated.
|
2.
When continue statement is encountered the entire loop is not terminated;
only that particular iteration is skipped.
|
3.
It uses a keyword break.
|
3.
It uses a keyword continue.
|
4.
It can be used in both loop and switch case.
|
4.
It can be only used in loop structure.
|
5.
Example:
#include<stdio.h>
#include<conio.h>
void
main( )
{
int
i;
for
(i=1;i<=10;i++)
{
if(i=
=2)
break;
printf("%d",i);
}
getch
( );
}
Output:
1
|
5.
example:
#include<stdio.h>
#include<conio.h>
void
main( )
{
int
i;
for
(i=1;i<=10;i++)
{if(i=
=2)
continue;
printf("%d\t",i);
}
getch(
);
}
Output:
1
3 4 5 6 7 8 9 10
|
Homework
Questions
C-1
(Introduction of C)
1. Define
variable and write the rules for variable naming in C programming.2. Define simple and compound statements. Describe logical operator with examples.
3. Define data type. Explain different types of data types used in C programming with examples.
4. What is an operator? Explain different types of operators used in C programming with examples.
5. Describe switch case statement with example.
6. What is variable? Write its types. Define the terms identifier and keywords with example.
7. Describe “sequence”, “selection” and “Loop” with flowchart and examples.
8. Differentiate between while and do-while loop with examples.
9. What is looping? Describe “For”, “while”, “do-while” loops with flowchart and appropriate examples.
Differentiate between break and continue statements with examples.
Fundamentals Program
1. Write a program to find out
whether the input number is even or odd?
#include<stdio.h> Output:
#include<conio.h> Enter a
number=4
void main() 4 is even number.
{
clrscr ();
int n;
printf(" Enter a number=
");
scanf(" %d ",
&n);
if(n%2==0)
printf(" %d is even
number. " , n);
else
printf(" %d is odd number.
" , n);
getch();
}
2. Write a program to find out
whether the input number is positive or
negative?
#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
int n;
printf(" Enter a number=
");
scanf(" %d " ,
&n);
if(n>0)
printf(" %d is positive
number. " , n);
else
printf(" %d is negative
number. " , n);
getch();
}
3. Write a program to find the
largest number among two numbers?
#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
int a,b;
printf("Enter any two
number=");
scanf("%d%d",&a ,
&b);
if(a>b)
printf(" %d is greater
number. " , a);
else
printf(" %d is greater
number. " , b);
getch();
}
4. Write a program to find the
smallest number among two numbers?
#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
int a,b;
printf("Enter any two
number=");
scanf("%d%d",&a ,
&b);
if(a<b)
printf(" %d is smaller
number. " , a);
else
printf(" %d is smaller
number. " , b);
getch();
}
5. Write a program to find the
largest number among three different
numbers?
#include<stdio.h>
#include<conio.h>
void main()
{
int a,b,c;
printf("Enter any three
number=");
scanf("%d%d%d",&a,&b,&c);
if(a>b&&a>c)
printf("%d is largest
number.",a);
else if(b>a&&b>c)
printf("%d is largest
numebr.",b);
else
printf("%d is largest
number.",c);
getch();
}
6. Write a program to find the
greatest number among four different
numbers?
#include<stdio.h>
#include<conio.h>
void main()
{
int a,b,c,d;
printf("Enter any four
number=");
scanf("%d%d%d%d",&a,&b,&c,&d);
if(a>b&&a>c&&a>d)
printf("%d is greatst
number.",a);
else
if(b>a&&b>c&&b>d)
printf("%d is greatest
numebr.",b);
else
if(c>a&&c>b&&c>d)
printf("%d is greatest
number.",c);
else
printf("%d is greatest
number.",d);
getch();
}
7. Write a program to check
whether the number entered by user is
divisible by 5 but not by 11?
#include<stdio.h>
#include<conio.h>
void main( )
{
int n;
printf("Enter a number
=");
scanf("%d",&n);
if(n%5==0&&n%11!=0)
printf(" %d is divisible
by 5 but not by 11.",n);
else
printf(" %d is not
divisible by 5 but not by 11.",n);
getch( );
}
8. Write a program to accept SP
and CP of an item and find whether there is
profit or loss?
#include<stdio.h>
#include<conio.h>
void main( )
{
int sp,cp,p,l;
printf("Enter the sp and
cp=");
scanf("%d%d",&sp,&cp);
if(sp>cp)
{
p=sp-cp;
printf("Profit=%d" ,
p);
}
else
{
l=cp-sp;
printf("Loss=%d "
,l);
}
getch( );
}
9. Write a program to calculate
and display the multiplication table of “n”?
#include<stdio.h>
#include<conio.h>
main( )
{
int n,i,ans;
printf("Enter any
number=");
scanf("%d",&n);
for(i=1;i<=10;i++)
{
ans=n*i;
printf(" %d * %d = %d \n
" , n, i, ans);
}
getch( );
}
10. Write a program to find the
factorial of a given number?
#include<stdio.h>
#include<conio.h>
void main( )
{
int n,i,f=1;
printf("Enter a
number=");
scanf("%d",&n);
for(i=1;i<=n;i++)
{
f=f*i;
}
printf(" Factorial of %d
=%d " , n , f);
getch( );
}
11. Write a program to display
the series upto 10th terms?
1 5 9 13 .............
#include<stdio.h>
#include<conio.h>
void main( )
{
clrscr();
int a=1,i;
for(i=1;i<=10;i++)
{
printf("%d\t" , a);
a=a+4;
}
getch( );
}
12. Write a program to display
first 10 even numbers?
#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
int i,a=2;
for(i=1;i<=10;i++)
{
printf(" %d \n " , a
);
a=a+2;
}
getch();
}
13. Write a program to display
the sum of “n” terms of even numbers?
#include<stdio.h>
#include<conio.h>
void main( )
{
int n , i , sum = 0;
printf("Enter a
number=");
scanf("%d",&n);
for(i=1 ; i<=n ; i++)
{
if( i%2 = = 0)
sum=sum+i;
}
printf("Sum of even
numbers up to %d = %d", n,sum);
getch( );
}
14. Write a program to enter
any number “n” and find the sum of the
numbers upto “n” using loop?
#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
int n,i,sum=0;
printf("Enter a number=");
scanf("%d",&n);
for(i=1;i<=n;i++)
{
sum=sum+i;
}
printf("Sum of numbers
upto %d =%d " , n , sum);
getch();
}
15. Write a program to check
whether the input number is prime or not?
#include<stdio.h>
#include<conio.h>
void main( )
{
clrscr();
int i, n;
printf("Enter a number =
");
scanf("%d",&n);
for(i=2;i<n;i++)
{
if( n % i = = 0)
{
printf(" %d is not prime
", n);
break;
}
}
if( i = = n)
printf(" %d is prime"
, n);
getch( );
}
16. Write a program to display
all prime numbers from 1 to 100?
#include<stdio.h>
#include<conio.h>
void main ( )
{
int n,i;
for(i=1;i<=100;i++)
{
for(n=2;n<i;n++)
{
if(i%n==0)
break;
}
if(i==n)
printf("%d\t",n);
}
getch();
}
17. Write a program to display
Fibonacci series i.e. 0 1 1 2 3 5 ... upto 10th
terms.
#include<stdio.h>
#include<conio.h>
void main( )
{
int a=0 ,b=1 , c, i;
printf("%d \t %d \t",
a , b);
for(i=1; i<=10; i++)
{
c=a+b;
a=b;
b=c;
printf(" %d \t " ,
c);
}
getch();
}
18. Write a program to display
1 for Sunday, 2 for Monday and so on?
[switch case example]
#include<stdio.h>
#include<conio.h>
void main ( )
{
int choice;
printf("Enter the number
of the day=");
scanf("%d",&choice);
switch(choice)
{
case 1:
printf("Sunday");
break;
case 2:
printf("Monday");
break;
case 3:
printf("Tuesday");
break;
case 4:
printf("Wednesday");
break;
case 5:
printf("Thursday");
break;
case 6:
printf("Friday");
break;
case 7:
printf("Saturday");
break;
default:
printf("Wrong
Choice");
}
getch( );
}
19. Write a program which finds
the sum, difference and product of two
numbers using switch case
statement?
#include<stdio.h>
#include<conio.h>
void main( )
{
clrscr();
int a,b,ch,s,d,p;
printf(" 1. Sum \n");
printf("2. Difference
\n");
printf("3. Product\n
");
printf(" Enter two
numbers=");
scanf("%d%d",&a,&b);
printf("Enter your choice
= ");
scanf("%d",&ch);
switch(ch)
{
case 1:
s= a+b;
printf("Sum of two
numbers=%d",s);
break;
case 2:
d=a-b;
printf(" Difference of two
numbers=%d",d);
break;
case 3:
p=a*b;
printf(" Product of two
numbers=%d",p);
break;
default:
printf("Wrong
Choice");
}
getch( );
}
20.Write a program to reverse a
number?
#include<stdio.h>
#include<conio.h>
void main( )
{
clrscr();
int n,r,num=0;
printf(" Enter any
number=");
scanf("%d",&n);
while(n!=0)
{
r=n%10;
num=num*10+r;
n=n/10;
}
printf("Reverse
order=%d",num);
getch( );
}
21. Write a program to display:
1
12
123
1234
12345
#include<stdio.h>
#include<conio.h>
void main()
{
int i,j;
for(i=1;i<=5;i++)
{
for(j=1;j<=i;j++)
{
printf("%d",j);
}
printf("\n");
}
getch( );
}
22. WAP to display: 1
22
333
4444
55555 ?
#include<stdio.h>
#include<conio.h>
void main ( )
{
int i,j;
for(i=1;i<=5;i++)
{
for(j=1;j<=i;j++)
{
printf("%d",i); }
printf("\n");
}
getch( );
}
23. WAP to display:
*
**
***
****
***** ?
#include<stdio.h>
#include<conio.h>
void main() {
int i,j;
for(i=1;i<=5;i++)
{
for(j=1;j<=i;j++) {
printf("*"); }
printf("
\n");
}
getch( ); }
24.
WAP to display 4321
321
21
1 ?
#include<stdio.h>
#include<conio.h>
void main ( ) {
int i,j;
for(i=4;i>0;i--)
{
for(j=i;j>0;j--)
{
printf("%d",j); }
printf("
\n");
printf(" "); }
getch( ); }
25. WAP to display 12345
1234
123
12
1 ?
#include<stdio.h>
#include<conio.h>
main() {
int i,j;
for(i=5;i>=1;i--
)
{
for(j=1;j<=i;j++) {
printf("%d",j); }
printf("
\n");
}
getch(); }
26. WAP to display 55555
4444
333
22
1 ?
#include<stdio.h>
#include<conio.h>
main( ) {
int i,j;
for(i=5;i>=1;i--)
{
for(j=1;j<=i;j++)
{
printf("%d",i);
}
printf("\n");
}
getch( );
}
27. WAP to display:
*****
****
***
**
* ?
#include<stdio.h>
#include<conio.h>
main( )
{
int i,j;
for(i=5;i>=1;i--)
{
for(j=1;j<=i;j++)
{
printf("*");
}
printf("\n");
}
getch( );
}
28. Write a program to check
whether the entered number is Armstrong or not [An
Armstrong number is that whose
sum of cube of digits is equal to number itself.
Example:-371=33
+73
+13
][1,153,370,371,407]
#include<stdio.h>
#include<conio.h>
void main()
{
int i,n,sum,j;
printf("Enter a
number=");
scanf("%d",&n);
sum=0;
i=n;
while(i!=0)
{
j=i%10;
sum=sum+j*j*j;
i/=10;
}
if(n==sum)
printf("%d is
Armstrong",n);
else
printf("%d is not
Armstrong",n);
getch();
}
29. Write a program to to enter
a string and check whether the entered string is palindrome
or not? [A string is said to be
palindrome if it remains same if we reverse it. Eg:-
ADA,LIRIL,MALAYALAM,MADAM]
#include<stdio.h>
#include<conio.h>
#include<string.h>
void main()
{
char str[100],temp[100];
printf("Enter a
string=");
scanf("%s",str);
strcpy(temp,str);
strrev(temp);
if(strcmp(temp,str)==0)
printf("%s is
palindrome",str);
else
printf("%s is not
palindrome",str);
getch();
}
30. Write a program to make a
report card of exam?
#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
char name[30];
int
cl,eng,nep,acc,eco,cmp,total;
float per;
printf("\nEnter the name
of a student=");
scanf("%s",name);
printf("\n Enter the
class=");
scanf("%d",&cl);
printf("\n Enter the marks
in English, Nepali,Account,Economics, Computer=");
scanf("%d%d%d%d%d",&eng,&nep,&acc,&eco,&cmp);
total=eng+nep+acc+eco+cmp;
per=total/5;
printf("NAME=%s\n" ,
name);
printf("CLASS=%d\n" ,
cl);
printf("TOTAL=%d\n" ,
total);
printf("Percentage=%0.2f\n"
, per);
{
if(eng>=35&&nep>=35&&acc>=35&&eco>=35&&cmp>=35)
printf("Result=Passed\n");
else
printf("Result=Failed\n");
if(per>=75)
printf("Division=Distinction");
else
if(per>=60&&per<75)
printf("Division=First");
else
if(per>=45&&per<60)
printf("Division=Second");
else
if(per>=35&&per<45)
printf("Division=Third");
else
printf("Division=Fail");
}
getch();
}
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