What is a logical value?
- [Voiceover] Logical values are used for…controlling conditionals and loops.…Here's a working copy of Logical.pl from…Chapter 4 of the execise files.…A logical value has one of two states,…true or false.…For example, in this case if x is equal to y…down there on line 10,…if x is equal to y and we know that…x is 1 and y is 1,…so x is equal to y so it should say true.…
I'm going to go ahead and build…and you see when I run it, it says true.…The If statement takes a logical value…to decide which block of code will be executed.…We'll cover If and other conditionals…in a later chapter.…The double equals sign tests for equality…and it returns true is the values are equal…and false is they are not.…In this case, $x is equal to $y,…so the logical value is true.…Now, just like in the C language,…zero is false and non-zero is true.…
If I say zero here and run it,…it says false but if I say any value that's not zero…and save and run that, then it says true.…Because of Perl's duck-typing model,…many things may be used in a logical context.…
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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