5.20. Perl until cycle

until statement when a given condition is false statement or group of statements is executed repeatedly.

until can be translated as “unless”.

5.20.1. Grammar #

The syntax format is as follows:

until(condition)
{
   statement(s);
}

Here, statement(s) can be a single statement or a block of code madeup of several statements.

condition can be any expression when the condition is false loop is executed when the. When the condition is true program flow continues with the next statement that follows the loop.

5.20.2. Flow chart #

In the chart until key point of a loop is that the loop may not be executed at all. When the condition is true skips the loop body and directly executes the following while next statement of the loop.

Example #

#!/usr/bin/perl$a=5;# execute until circulateuntil($a>10){printf"a's value is
:$a\\n";$a=$a+1;}

Variables in the program $a execute the loop body less than 10:00, in the variable $a greater than 10:00, exit the loop.

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

The value of a is: 5
The value of a is: 6
The value of a is: 7
The value of a is: 8
The value of a is: 9
The value of a is: 10