Learn the distinctions between statements and expressions.
- [Voiceover] In Perl, the concepts of statements…and expressions overlap a bit.…Let's take a look at what this means.…Here's a working copy of countlines3.pl…from Chapter 3 of the exercise files.…In general, a statement tells the computer…what action to take,…and an expression represents a value.…A given line of code may be a statement,…an expression, or both.…For example, line 13 contains an expression.…The value is the name of the file,…either from the command line via the shift operator…or from the literal string linesfile.txt.…
An expression is anything that returns a value,…so in this case, the literal string returns a value,…the shift returns a value, the result of shift…or the literal string returns a value,…and the assignment returns a value.…The assignment is also a statement.…Line 15 is a statement.…It calls built in function, say, to display…a string on the console.…In Perl, a semicolon is used to separate statements.…
In other words, the semicolon at the end of line 15…is actually optional.…For example, if I run this, you see we have -…
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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