Hi out there, after looking at rails and the pickaxe book (not totally red yet, just used as a reference) I still wondering when to use just a construct :a => something What does it stands for and when to use it? Please apologize if it's a basic questions, but I can't realize myself the usage. If someone has a page no. in the pickaxe book, I'm glad to read the chapter ;) Thanks in advance.
on 2005-12-04 18:50
on 2005-12-04 18:54
Look up Symbols. The colon (:) is used to create them. The basic idea is that if you are using a String as the key or value for a hash in many places, it is more efficient to use a Symbol. Ryan
on 2005-12-04 19:06
It helps not to think of :a as a variable (you won't see it on left-hand-side). It is an identifier called a 'symbol' or in some other languages an 'atom' or 'interning.' A symbol is guranteed to be the same (for the same string) everywhere it is used. Atoms can be introduced ad-hoc in your code and anywhere you use the same atom is assured to match :foo != :bar but :foobar == :foobar. It is a space and time saver to use symbols as constants, keys etc. rather than using a string constant. More on Pg. 308 of Pickaxe 2nd edition. <Mark/>
on 2005-12-04 20:03
Hi Mark, Mark Ericson wrote: > More on Pg. 308 of Pickaxe 2nd edition. Thanks a lot. That are these kind of programming constructs I've to learn. I'll read the pages. g,