- 01Setting up (what you'll need)
- 02Your first output (print)
- 03Variables (scalar variables, $)
- 04Branching (the if statement)
- 05Repeating (the for loop)
- 06Writing a subroutine (a function)
- 07Repeating (the while loop)
- 08Working with arrays (@)
- 09Working with hashes (%)
- 10Regular expression matching
- 11Substitution with regular expressions (s///)
- 12Working with strings
- 13References
- 14Anonymous subroutines
- 15File input and output, the basics
- 16Modules and use strict / warnings
- 17The ternary operator
- 18Sorting (sort)
- 19Packages and the basics of object orientation
- 20[Project] Build a small inventory system
Repeating (the while loop)
This lesson covers the while statement, which repeats only while a condition holds.
Writing while (condition) { ... } repeats the block for as long as the condition is true.
The sample code prints a number and increases it by one while $count is 3 or less.
A common early stumble is forgetting to update the counter inside the loop and ending up in an infinite loop. Whenever you use a while statement, make sure something in the body eventually makes the condition false.
In professional work, while loops are the usual choice for reading a log file line by line and processing as you go.
๐งช This site can't compile or run Perl directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser โ nothing is sent anywhere).