Basic Ruby Language Elements

Ruby module R103

Exercises, examples and other material relating to training module R103. This topic is presented on public courses Learning to program in Ruby, Ruby Programming

Background

Ruby hasn't re-invented everything - it's taken the good basics from variables through "Bodmas" to statement structure and commenting from best practise elsewhere.

Articles and tips on this subject		updated
4504	Where does Ruby load modules from, and how to load from current directory All (scripting) languages allow you to load code from other supporting source files, using keywords like use, load, source and include. In Ruby, the most common way to load other code is to require it - and if you use the require method you'll load in code from another file which will be assumed to ...	2015-06-03
4369	Ruby - the second rung of learning the language When you're learning a programming language - or to program - your text / tutor will almost inevitably start with "Hello World" - a program to display a string of text. That's chosen as the first example as it shows you how to enter and store you program, it shows you any steps necessary to convert ...	2014-12-30
4324	Learning to program - variables and constants Further material from our "learning to program in ...." courses ... an introduction to variables and constants variable basics Information - data - needs to be stored in a program between statements. Or rather it needs to be stored in the computer's memory. At the lowest of levels, that's a binary ...	2014-11-22
3917	BODMAS - the order a computer evaluates arithmetic expressions What order does a computer program use to evaluate expressions? If I write 2 + 3 * 4 + 5 does it start off, left to right ... 2 + 3 is 5 5 * 4 is 20 20 + 5 is 25 No! it does not, even though the newcomer might think that was the most natural way for ...	2012-11-10
3758	Ruby - standard operators are overloaded. Perl - they are not Ruby has been described to me as "What Perl 5.5 should have been", but that statement is a severe dis-service to Ruby, and to Perl. Ruby is a new language, and if you're moving into Ruby from Perl, you'll do best not to assume even the basics from Perl. A lot has been learend from Perl, for sure, ...	2012-06-16
3430	Sigils - the characters on the start of variable names in Perl, Ruby and Fortran A sigil (from Latin sigillum "seal") is a symbol created for a specific magical purpose. A sigil is usually made up of a complex combination of several specific symbols or geometric figures, each with a specific meaning or intent. In computer programming, a sigil is a special symbol attached to a variable ...	2011-09-10
3278	Do I need to initialise variables - programming in C, C++, Perl, PHP, Python, Ruby or Java. Starting with a clean slate. Are variables initisialised, and if so, how? Even with this fundamental question, languages vary considerably. C and C++ From my (e)mailbag ... """In a piece of code weâ€™ve written we declare an array, but we do not fill the elements with values, we assume (dangerous ...	2011-05-05
2617	Comparing floating point numbers - a word of caution and a solution "Think of a number between 5 and 15. Double it. Add fourteen. Halve it. Take away the number you first thought of. Is the result 7?" We all played games like that as children, thinking of the number 0 ourselves so that we could do an easy calculation and impress our friends. And the result was 7 ... ...	2010-02-02
2613	Constants in Ruby If you want to have a read only variable in Ruby, start its name with a capital letter (and you may like to go with a convention of using capitals right through the variable name). Note that a Ruby constant - a name starting with a capital - hasa global scope, just like a variable name that starts with ...	2010-02-01 (short)
2296	Variable scope - what is it, and how does it Ruby? Variables have different "scopes" - in other words, a name that is allocated to a piece of computer memory and subsequently used to refer to that memory may be 'know about" to your program only within a very small area, or much more widely. It's the same IRL ("In Real Life") - consider you, Dad, Graham ...	2009-07-19
2287	Learning to program in Ruby - examples of the programming basics We so often overlook the basics of programming, and yet they are so fundamental to good code - understanding things like how widely variables can be seen (also known as variable scope), what happens when you divide two numbers (do you get a decimal result or is the remainder thrown away), and how do ...	2009-07-15
986	puts - opposite of chomp in Ruby In Ruby, the chomp method removes the last character of a string if it's a line separator. The puts method adds a new line character on to the output unless there's one already present. In Perl and other languages, a great deal of time and mental agility is expended in remembering where there are (and ...	2006-12-15 (short)

Examples from our training material

bluepeter	Throw a die and track sum of throws
bw.rb	Formatting strings and conversions
calc.rb	Some early gotchas!
calcbetter.rb	A simple calculation in Ruby
d2.4	Easier output formatting in double quoted strings
d2.5	Calculations within double quotes
floater	Floating point rounding errors
muck	Common Ruby Pitfalls
print.rb	Print alternatives
rub1	FAILS to continue a line
x01	Constants in Ruby

Background information

Some modules are available for download as a sample of our material or under an Open Training Notes License for free download from [here].

Topics covered in this module

Structure of statements and comments.
Variables and constants.
Operators.
Assignments, calculations, etc.
Integer, float and string formats.
Single and double quotes, here documents, general strings.

Complete learning

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