Listing of standard methods

For 2023 (and 2024 ...) - we are now fully retired from IT training.
We have made many, many friends over 25 years of teaching about Python, Tcl, Perl, PHP, Lua, Java, C and C++ - and MySQL, Linux and Solaris/SunOS too. Our training notes are now very much out of date, but due to upward compatability most of our examples remain operational and even relevant ad you are welcome to make us if them "as seen" and at your own risk.

Lisa and I (Graham) now live in what was our training centre in Melksham - happy to meet with former delegates here - but do check ahead before coming round. We are far from inactive - rather, enjoying the times that we are retired but still healthy enough in mind and body to be active!

I am also active in many other area and still look after a lot of web sites - you can find an index ((here))

More Classes and Objects example from a Well House Consultants training course
More on More Classes and Objects [link]

This example is described in the following article(s):
• Standard methods available on all objects in Ruby - [link]

Source code: stanley Module: R108

# List of standard methods, and some examples of their use.

class Thing
        end

widget = Thing.new
can_do = widget.methods

for explain in can_do
        p explain
end

# Some testing examples

widget.display
print "\n"
puts widget.inspect

p widget.to_a

__END__

Sample outputs from that end section

#<Thing:0x10b13e140>
#<Thing:0x10b13e140>
stanley:18: warning: default `to_a' will be obsolete
[#<Thing:0x10b13e140>]

Standard methods - In Alphabetic order:

"==" - equality / same value
"===" - equality test for case
"=~" - looks like (regular expression)
"__id__" - give me a unique object no.
"__send__"
"class" - what type of object is this? (Yuk!)
"clone" - duplicate object contents (shallow copy?)
"display" - same as to_s but NOT overridden when you override to_s
"dup" - ?? Deep copy
"enum_for"
"eql?" - test for identical object
"equal?" - test for one and the same object
"extend"
"freeze" - makes it read-only from now on (prevents modification)
"frozen?" - Checks if proven
"hash"
"id"
"inspect" - like "p" but returns string, doesn't output it
"instance_eval"
"instance_exec"
"instance_of?" - check object type (give class name)
"instance_variable_defined?"
"instance_variable_get"
"instance_variable_set"
"instance_variables"
"is_a?" - check object type (unlike class uses inheritance)
                  Often better that "class" or "instance_of?"
"kind_of?" - same as is_a?
"method" - returns a method object
"methods" - Array of methods
"nil?" - does it point to the nil (false) object?
"object_id"
"private_methods" - selectively lists only private methods
"protected_methods"
"public_methods"
"respond_to?" - check whether a method is there somewhere in the inheritance tree
"send" - call a method named as parameter
                thing.send(:setage,25) is equivalent to thing.setage(25)
"singleton_methods" - listing extra methods that apply to this object only
"taint" - mark as "dirty" (so can't be used to open file, for example)
"tainted?" - is it dirty?
"tap" - new in Ruby 1.9; act on object in block but also return object
                avoids breaking a pipeline
"to_a" - to array
                [default is deprecated]
"to_enum"
"to_s" - to string (for printing)
"type"
"untaint" - mark it clean!

Learn about this subject

This module and example are covered on the following public courses:
* Learning to program in Ruby
* Ruby Programming
Also available on on site courses for larger groups

Books covering this topic

Yes. We have over 700 books in our library. Books covering Ruby are listed here and when you've selected a relevant book we'll link you on to Amazon to order.

Other Examples

This example comes from our "More Classes and Objects" training module. You'll find a description of the topic and some other closely related examples on the "More Classes and Objects" module index page.

Full description of the source code

You can learn more about this example on the training courses listed on this page, on which you'll be given a full set of training notes.

Many other training modules are available for download (for limited use) from our download centre under an Open Training Notes License.

Other resources

• Our Solutions centre provides a number of longer technical articles.
• Our Opentalk forum archive provides a question and answer centre.
• The Horse's mouth provides a daily tip or thought.
• Further resources are available via the resources centre.
• All of these resources can be searched through through our search engine
• And there's a global index here.

Web site author

This web site is written and maintained by Well House Consultants.

Purpose of this website

This is a sample program, class demonstration or answer from a training course. It's main purpose is to provide an after-course service to customers who have attended our public private or on site courses, but the examples are made generally available under conditions described below.

Conditions of use

Past attendees on our training courses are welcome to use individual examples in the course of their programming, but must check the examples they use to ensure that they are suitable for their job. Remember that some of our examples show you how not to do things - check in your notes. Well House Consultants take no responsibility for the suitability of these example programs to customer's needs.

This program is copyright Well House Consultants Ltd. You are forbidden from using it for running your own training courses without our prior written permission. See our page on courseware provision for more details.

Any of our images within this code may NOT be reused on a public URL without our prior permission. For Bona Fide personal use, we will often grant you permission provided that you provide a link back. Commercial use on a website will incur a license fee for each image used - details on request.

You can Add a comment or ranking to this page

Further Examples

O1.rb - Amending a base class even after it has been extended

O2.rb - Copy v clone

attr - attribute accessors

cmquick - static and dynamic member variables and methods

d4_2 - Single class example for extension by inheritance

d4_3 - Object and Class variables (dynamic and static)

d4_4 - Static Method

d4_5 - Inheritance in Ruby

disc2 - Comparator methods (larger and smaller)

dub2 - With $ - variables are global