Data Types

Data Types

• Scalars
   
• Arrays & Lists
   
• Hashes
   
• References
   
• Filehandles

It's all about context

• Perl is smart enough to know how you're using something
   
• Numerics can be strings; strings can be numerics
   
• Arrays can be scalars
   
• Hashes can be arrays
   
• Arrays can be hashes

Scalars

• Single value
   
• Arbitrary large
   
• Can contain binary data, even nulls.
   
• Can be numeric or string, depending on context

Arrays/Lists

• Arbitrary-sized array of scalars
   
• Can contain any scalar
   
• Used when you want to preserve order of something

Hashes

• Collection of scalars
   
• Keyed by a unique case-sensitive string
   
• Useful for lookups or checking for existence
   
• Same as associative arrays in awk, or the CMap class in MFC.

References

• Is a scalar, and can be used anywhere a scalar can
   
• Perl version of pointers