Garrick van Buren

Day 7, playing catch-up.

I’m continually impressed with how concise the Ruby language is. As I mentioned in Day 4, Ruby frowns upon loops. I’m getting the impression Ruby also frowns upon taking up 2 or more lines to describe an action. Slagell’s examples of doing something a traditional way take up multiple lines, his here’s-a-better-way examples are single line. If we compare writing code to writing words and say each a chunk of code is a paragraph and each line of code is a sentence. Writing Ruby is more like dialog than narrative.

Note to self:
In Ruby, double quotes acknowledges backslash-escaped characters, i.e. "n" = new line. Single quotes will not, i.e. 'n' = n. Same is true for evaluating expressions within #{...}

Two Cool Things in Ruby:

1. Chained Assigment
   Want to give a number of variables the same value?
   DaveSpeaks = JoeSpeaks = KatSpeaks = FrankSpeaks = "English"
2. Multiple Assignment
   Want to quickly set the values of multiple variables at the same time?
   DaveSpeaks, JoeSpeaks, KatSpeaks = "English", "Dutch", "German"

The start of the day has quite a bit on binary numbers. I’m not sure when binary arithmetic will come in handy (a position I also expressed regarding Jr. High Algebra) but it’s nice to know it’s here when the need arises. The example Slagell offers at the chapter end feels like a band-aid for a poorly designed system. If any of you following along can provide a comment on when it’s beneficial to use binary arithmetric, I’d be extremely grateful.

As I finished up today’s exercises, Bic Runga’s ‘Listening for the Weather’ came through my iTunes. What an excellent way to wrap up Day 7.

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This post documents my journey through Sam’s Teach Yourself Ruby in 21 days. I’ll be joining Al Abut in his effort to learn Ruby and blog along the way.

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Day 6, How to deal with files and other data streams.

What’s a reliable way to get the last item in an array? ask for the -1 item, i.e. array[-1].
Finally, a logical reason to start arrays at 0 rather than 1 – so we can count backwards.

Looks like the “then” part of an “if…then” statement can come first. As in this example from the book, removing a leading zero from a decimal number.
avg[0,1] = '' if avg[0, 2] == "0."

This will take some getting accustomed to. I’m more familiar with it written this way:

if avg[0,2] == "0."
avg[0,1] == ''
end


To accommodate When Bad Things Happen, Ruby has a pretty cool construct:

begin
#...
rescue BadThing1Happened
#...
rescue BadThing2Happened
#...
end


Two cool things here; first – this seems like a simple way to write more readable code – error conditions or otherwise, second – the word “rescue”, makes you feel like a superhero for catching Bad Things. Incentive enough for writing better code.

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This post documents my journey through Sam’s Teach Yourself Ruby in 21 days. I’ll be joining Al Abut in his effort to learn Ruby and blog along the way.

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Day 5 is all about objects and their methods.

Remember a few months back when Apple introduced the Shuffle? Everyone was up-in-arms about it’s lack of screen and how it was useless an mp3 player without a screen is. When in-fact, the lack of screen simplifies and improves the device a great deal.

Ruby is like that; elegant, well thought out, useful, challenging convention. Case in point:

Methods names can end with ‘ =’. Conceptually treating a method’s values as variables. It not only saves keystrokes in comparison to the traditional methodName(value) convention – it more accurately maps to what’s being described.

Add to that, a built-in method for creating read & write methods – attr_accessor, an I’m understanding why Ruby is called the Programmers’ Best Friend.

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This post documents my journey through Sam’s Teach Yourself Ruby in 21 days. I’ll be joining Al Abut in his effort to learn Ruby and blog along the way.

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Day 4 – Iterators.

First, all chapters in programming books should start with quotes from Steve Martin (t).

Second, what’s a language without a convoluted loop syntax to geek out on? Geeez. I thought the purpose of learning to program was the same as learning Arabic from the Defense Language Institute – “because you can’t.” Ruby has iterators for logical, readable code? This means I might actually get something built rather than just debugging loops.

I’ve mentioned before how much I enjoy Slagell’s writing. I also like how the solutions to the exercises are listed immediately after the exercises. This isn’t typical, at in my collection of programming books. It makes getting un-stuck and getting the point much quicker.

Tip: Here’s how I’m remembering how the ‘step’ iterator works:

start.step(to, by)


an example to display all the odd numbers from 5 to -15

5.step(-15, -2)


Quite a few years back I was talking with a programmer/designer (in contrast to my designer/programmer) who didn’t like AppleScript because it was “too much like English”. With syntax like:

• 3.times to do something, well, 3 times and
• 10.downto(1) to count down from 10 to 1

I don’t think he’d like Ruby for the exact same reason – if not more so.

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This post documents my journey through Sam’s Teach Yourself Ruby in 21 days. I’ll be joining Al Abut in his effort to learn Ruby and blog along the way.

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