- A statement or a set of statements that is executed repeatedly is called a loop.
- Loop is executed until the given condition remains true.
- Three loops in C are While Loop Do-While Loop For Loop
While Loop:
- Used to execute a statement or set of statements as long as the given condition remains true.
- Syntax of the “While” loop is
while (condition)
{
statement (s);
}
Example:
#include <stdio.h> #include <conio.h> main ( )
{
int c=1;
while (c<6)
{
printf (“I Love Pakistan\n”); c=c+1;
}
getche( );
}
Do-While Loop:
Used to execute a statement or set of statements.
Just like while loop but in this loop the condition is tested after executing the statements of the loop.
Syntax of the “While” loop is
do
{
statement (s);
}
while (condition);
Example:
#include <stdio.h> #include <conio.h> main ( )
{
int c=1; do
{
printf (“I Love Pakistan\n”); c=c+1;
}
while (c<6); getche( );
}
For Loop:
- Used to execute a statement or set of statements as long as the given condition remains true.
- Also called Counter loop.
- It has following parts
1. Initialization
2. Condition
3. Increment or Decrement
4. Body of the Loop
- General syntax of For Loop is for (initialization; condition; increment / decrement)
{
Statements;
}
Example:
#include <stdio.h> #include <conio.h> main ( )
{
int a;
for (a=5; a<15; a++)
{
printf (“I Love Pakistan\n”);
}
getche( );
}
NESTED LOOPS:
A loop can be declared inside another loop called nested loop.
Loops can be nested For-Loop, While Loop, Do-While Loop or mixture of these.
Example:
#include <stdio.h> #include <conio.h> main ( )
{
int a, b;
for (a=1; a<5; a++)
for (b=1; b<3; b++)
{
printf (“I Love Pakistan\n”);
}
getche( );
}