Perl until loop

Author：Eve Cole Update Time：2024-12-24 10:22:28

The until statement repeatedly executes a statement or group of statements when the given condition is false.

grammar

The syntax format is as follows:

 until(condition){ statement(s);}

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

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

flow chart

In the diagram, the key point about the until loop is that the loop may not execute even once. When the condition is true, the loop body will be skipped and the next statement immediately following the while loop will be executed directly.

Example

#!/usr/bin/perl $a = 5 ; # Execute until loop until ( $a > 10 ) { printf " The value of a is: $a n " ; $a = $a + 1 ; }

In the program, when the variable $a is less than 10, the loop body is executed, and when the variable $a is greater than 10, the loop is exited.

Executing the above program, the output result is:

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