Discover how to create static variables with the "state" keyword.
- [Voiceover] Beginning with Perl 5.10,…you can create static variables with the state feature.…Here is a working copy of func.pl…from chapter ten of the exercise files.…So I'm gonna come down here to my function,…and I'm going to declare a variable.…And then I'm going to increment that variable and print it,…saying "say ++$n" like that.…And so that will increment n,…so instead of 10, it will be 11,…and it'll pass that 11 to "say",…and when I run it, you see it says 11.…
Now here is the interesting thing.…If I run this function five times,…each time we get a new copy of n,…which is discarded at the end of the block.…And so, each time it'll print the number 11.…So I'll run this, and you see we get number 11 five times.…On the other hand, if instead of "my"…I use the keyword "state",…now we have a static variable instead of a dynamic variable.…And when I run this,…you notice that the value increases each time.…
So this is what's called a static variable.…Instead of there being a new copy of n…every time the function is called,…
Watch to learn the details of the Perl syntax, from variables, conditionals, loops, and data structures to regular expressions, functions, and references. A quick-start guide is included for experienced developers who want to get up and running with Perl 5 fast, and the entire course is recommended for both new and experienced programmers alike. Later chapters cover file handling and reusing code with Perl modules, plus Perl best coding practices.
- Understanding Perl's general syntax and the anatomy of a Perl script
- Writing statements and expressions
- Creating assignments
- Working with variables and strings
- Using data types effectively
- Defining logical flow with conditionals and loops
- Using special variables
- Using Perl operators
- Performing simple Perl programming tasks with expressions
- Matching data
- Defining and calling functions
- Using references
- Handling files in the file I/O
- Using built-in functions
- Reusing code with modules
- Coding with Perl best practices
Skill Level Intermediate
1. Setting Up
About Perl3m 36s
2. Quick Start
3. Basic Syntax
4. Values and Variables
7. Special Variables
9. Regular Expressions
11. References and Structures
12. File I/O
13. Built-In Functions
15. Best Practices
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