CODEWITHSUNDEEP
rubyclasssyntaxaccessor
HungryCoder
HungryCoder

Reputation: 7616

confused with Ruby accessor methods

i'm really confused how to name method names in Ruby classes. if i create an accessor like: attr_accessor :name

it creates to methods: name and name=

but when i call the second method with a whitespace between the 'name' and '=' it works

'n.name=' and 'n.name =' both works.

i read somewhere that Ruby ignores whitespaces. Well then, why a method written by me does not work when i call it with whitespace?

def getname end

if i call this way, it doesn't work. why? t.get name

i'm not surprised as it does not work. but i'm confused how the setter method (name=) works then?

thanks in advance.

Upvotes: 0

Views: 675

Answers (2)

louielouie
louielouie

Reputation: 14941

Setters are special in Ruby.

In fact, defining a method name ending in an equals sign makes that name eligible to appear on the left-hand side of an assignment.

from http://www.ruby-doc.org/docs/ProgrammingRuby/html/tut_classes.html

Assignments are defined in Ruby as:

An assignment statement sets the variable or attribute on its left side (the lvalue) to refer to the value on the right (the rvalue).

from http://www.ruby-doc.org/docs/ProgrammingRuby/html/tut_expressions.html

So n.name= is calling the setter name= directly.

n.name = is using this special treatment of setters by the fact that it ends in an =, to make it so that you can use it as the lvalue (that is, it can appear on the left side) in an assignment.

Upvotes: 3

Phil
Phil

Reputation: 420

getName is the name of the method, so you cannot have whitespace in that because then it thinks it is two methods or maybe a parameter, that is why we camal case to make it readable. But the equal sign is an operand and there can be space around that. Its the same as say '2+2' and '2 + 2'. Hope that helps

Upvotes: 1

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