Perl do…while cycle

Not like for and while loops, they test the loop conditions at theloop header. In Perl the language do...while loop checks itscondition at the end of the loop.

do...while cycle vs. while loop is similar, but ``do…while``loop ensures that the loop is executed at least once.

Grammar

The syntax format is as follows:

do
{
   statement(s);
}while( condition );

Notice that the conditional expression appears at the end of the loop, so the statement(s) , it will be executed at least once before the conditionis tested.

If the condition is true control flow will jump back to the above do and then re-execute the statement(s) . This process is repeated over and over again until a given condition becomes false so far.

Flow chart

Example

#!/usr/bin/perl$a=10;# execute do...while loop do{printf"a
The value of is :$a\\n";$a=$a+1;}while($a<15);

Execute the above program, and the output is as follows:

The value of a is: 10
The value of a is: 11
The value of a is: 12
The value of a is: 13
The value of a is: 14