While loop
It executes one or more statements while the given condition remains true.It is useful when number of iterations is unknown.
Syntax
initialization
while (condition)
{
statement;
increment/decrement;
}
Flow chart
Syntax
initialization
while (condition)
{
statement;
increment/decrement;
}
Flow chart
Example
#include<stdio.h>
#include<conio.h>
void main (void)
{
int n;
n=1;
clrscr();
while (n<=5)
{
printf("\n %d",n);
n++;
}
getch();
}
#include<stdio.h>
#include<conio.h>
void main (void)
{
int n;
n=1;
clrscr();
while (n<=5)
{
printf("\n %d",n);
n++;
}
getch();
}
Do while loop
Do while loops are useful where loop is to be executed at least once. In do while loop condition comes after the body of loop.This loop executes one or more statements while the given condition is true.
Syntax
initialization
do
{
statement(s);
increment/decrement;
}
while (condition);
Flow chart
Syntax
initialization
do
{
statement(s);
increment/decrement;
}
while (condition);
Flow chart
Example
#include<stdio.h>
#include<conio.h>
void main (void)
{
int a;
a=1;
clrscr();
do
{
printf("\n %d",a);
a++;
}
while (a<=5);
getch();
}
#include<stdio.h>
#include<conio.h>
void main (void)
{
int a;
a=1;
clrscr();
do
{
printf("\n %d",a);
a++;
}
while (a<=5);
getch();
}
For loop
For loops are used when the number of iterations is known before entering the loop. It is also known as counter-controlled loop.
Syntax
for (initialization;condition;increment/decrement)
{
statement()s;
}
Flow chart
Syntax
for (initialization;condition;increment/decrement)
{
statement()s;
}
Flow chart
Example
#include<stdio.h>
#include<conio.h>
void main (void)
{
int n;
for(n=1;n<=5;n++)
{
printf("\n %d",n);
}
getch();
}
#include<stdio.h>
#include<conio.h>
void main (void)
{
int n;
for(n=1;n<=5;n++)
{
printf("\n %d",n);
}
getch();
}