programming-for-dummies

518
Creating Objects
When defining a hash with multiple lines, use square brackets.
To retrieve data from a hash, identify the hash name and a key value, such as
puts hashname[“key”]
So if you wanted to retrieve data stored under the key “pi”, you could do
the following:
hashname = Hash.new
hashname[“pi”] = 3.14
puts hashname[“pi”]
The first line creates a hash data structure. The second line stores the value
3.14 into the hash using the key “pi”. The third line prints out the value
identified by the “pi” key in the hash data structure.
Creating Objects
Ruby supports object-oriented programming. To create an object, you must
define a class, which specifies the properties and methods, such as
class Classname
def propertyname
@propertyname
end
def propertyname=(propertyname)
@propertyname = propertyname
end
def methodname(parameter list)
commands
end
end
To create an object, you must use the following syntax:
objectname = Classname.new
To assign a value to an object’s property, you need to specify the object
name and the property you want to use, such as
objectname.propertyname = value