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Perl syntax
Summarize basic syntax such as if statement and for statement. The Perl grammar stuff is in the syntax article. Please use it as a syntax reference. It also contains an introductory article on syntax.
Syntax check
You can check if Perl's syntax is correct with the "-c" option.
perl -c myapp.pl
String syntax
Introducing the syntax for strings.
| Single quote string | Character strings that cannot use escape sequences such as variable expansion and line break characters |
| Double quoted string | A string (overwritten) that can use escape sequences such as variable expansion and line break characters |
| Variable expansion | Use variable in strings |
| Escape sequence | Special characters that can be used in strings |
| Escape sequence of single quoted strings | Escape sequence of single quoted strings |
| Double quote string escape sequence | Escape sequence of double quoted strings (overwritten) |
Regular expression syntax
The regular expression syntax is explained in detail in the following articles.
Conditional branching syntax
Introducing the syntax for conditional branch.
| if | Conditional branch |
| if ～ elsif ～ else | Multiple conditional branches |
| unless | Conditional branch that negates the condition |
| or | Conditional branching using OR |
| goto | Unconditional jump |
| if modifier | Postfix if |
| unless modifier | Postfix unless |
Please refer to the following article for details on conditional branch using if statement.
Loop syntax
Introduces syntax for control structures such as repetition.
| while | General-purpose loop syntax |
| for | Repeated statement using index |
| foreach | Process the elements of the array in order |
| next | Jump to the beginning of the next iteration |
| last | Get out of the loop |
| redo | Loop redo |
| do ～ while | Execute the process once before judging the condition of the loop |
| continue | Run just before the condition is reevaluated |
Variable syntax
Introduces the syntax for variable declarations.
| my | Declaration of a lexical variable |
| our | Declaration of a package variable |
| local | Declaration of a local variable |
| Default variable | Default variable $_ |
Comment syntax
Here's the syntax for writing comments in Perl.
| Comments | Single-line and multi-line comments |
Subroutine syntax
Explains the syntax related to subroutine.
| AUTOLOAD | Subroutine autoload function |
Module syntax
Describes the syntax for modules.
| package | Package declaration | tr>
| use | Load modules at compile time |
| require | Load the module at run time |
| do | Read the configuration file |
Object - oriented syntax
| DESTROY | Destructor |
Perl - specific syntax
Describes the syntax specific to Perl.
| Context | Scalar context and list context |
| Boolean value | Boolean value in Perl |
| Type glob | Data slot |
| POD (Plain Old Documentation) | How to write a document |
| List assignment | Substitution using a list |
Numerical calculation syntax
I will explain the syntax related to numerical calculation.
| Numeric literals | Numeric representation in Perl |
Related information
See the following pages for Perl operators, builtin functions, predefined variable and modules.