Perl while Loop

The Perl while loop is used to iterate the part of program or statements many times.

In while loop, condition is given before the statement. When loop execution starts, it first checks whether the condition is true or false. If condition is true,loop executes. If condition is false, the loop terminates out of the loop.

Syntax

The syntax of while loop in Perl language is given below:

snippet

while(condition){
//code to be executed
}

Flowchart of while loop in Perl

Example

snippet

$i = 1;
# while loop execution
while( $i <= 10 ){
   printf "$i\n";
   $i++;
}

Output

1 2 3 4 5 6 7 8 9 10

Nested While Loop

Example

In nested while loop, one while loop is used inside another while loop. The inner while loop is executed completely while outer loop is executed once.

snippet

$i = 1;
# while loop execution
while( $i <= 3 ){
   $j = 1;
   while( $j <= 3 ){
   printf "$i $j\n";
   $j++;
}
$i++;
}

Output

1 1 1 2 1 3 2 1 2 2 2 3 3 1 3 2 3 3

Infinite while Loop Example

To create infinite while loop, pass true as the test condition. Press ctrl + c to stop the loop execution.

Example

snippet

while(true)
{
	printf"Infinitive While Loop\n";
}

Output

Infinitive While Loop Infinitive While Loop Infinitive While Loop Infinitive While Loop Infinitive While Loop ctrl+c