1.
What every beginning
developer should know
Andy Lester
CodeMash, January 10, 2019
@petdance
andy@petdance.com

2.
What brings you
to this talk?

3.
Where I'm coming from
32 years of software development
Manager, team leader, hire programmers
I spend a lot of time on StackOverflow
(That's a lot of beginning devs)

4.
Tools of the trade

5.
Be able to live
outside the IDE

6.
Version Control Systems
Branching
Merging
Using VCS as a team
How to write a commit message

7.
Let the language help
gcc warnings -Wall and -Wextra
JavaScript 'use strict'
PHP's error_reporting(E_ALL);
Perl's use warnings; use
strict;

8.
Static analysis tools
Python: pylint, vulture, mypy
PHP: phan, PHPMD
Go: golint
Perl: Perl::Critic
Javascript: JSLint, jshint, flow
SQL: sqlcheck
C/C++: splint, oclint, cppcheck
https://matthias-endler.de/awesome-static-analysis/

9.
Serious editing
vim
emacs
Atom
Eclipse
Not Notepad for God's sake

10.
Make, shell scripts,
and repeatability
Computers do the drudge work.
Humans do the thinking.

11.
HTML + CSS

12.
HTML+CSS
Chances are your front end will be a
browser
Just the basics
Separating structure from display

13.
# ❌ Physical markup
<b><font size="+2">Customers</b></font>
<p>Lorem ipsum <i>cupit non proident</i></p>
# ✅ Semantic markup
<h1>Customers</h1>
<p>
Lorem ipsum <span class="emphasis">cupit
non proident</span>
</p>

14.
SQL

15.
"All the SQL I know I learned
on the job. Why are
databases an elective? What
doesn’t use a database?"

16.
ID Name Manager Salary
1 Smith N 1,000
2 Jones N 1,200
3 Franklin Y 1,500
4 Davis N 800
# 10% raise for non-managers
while (employee = read_employee())
if employee.manager = 'N'
employee.salary *= 1.10
write_employee( employee )

17.
ID Name Manager Salary
1 Smith N 1,000
2 Jones N 1,200
3 Franklin Y 1,500
4 Davis N 800
# 10% raise for non-managers
UPDATE employees
SET salary = salary * 1.10
WHERE manager = 'N';

18.
Different mindset
# Iterative
while ( employee = read_employee() )
if employee.manager = 'N'
employee.salary *= 1.10
write_employee( employee )
-- Declarative
UPDATE employees
SET salary = salary * 1.10
WHERE manager = 'N';
-- Plus it's faster!

19.
Regular Expressions

20.
Two big needs
Validating data
Searching source code
NOT parsing

21.
Validating strings
Part numbers must be like "ABCD-12"
Four alphas
Hyphen
Two digits

22.
Four alphas, hyphen,
two digits
ok = TRUE # Assume OK
for pos ( 0..3 )
if ( !isalpha( substr(partno,pos,1 ) )
ok = FALSE
if substr(partno,4,1) != '-'
ok = FALSE
for pos ( 5..6 )
if ( !isdigit( substr(partno,pos,1 ) )
ok = FALSE

23.
Or...

24.
Four alphas, hyphen,
two digits
/^[A-Z]{4}-d{2}$/

25.
Four alphas, hyphen,
two digits
# Perl
$ok = $partno =~ /^[A-Z]{4}-d{2}$/;
# PHP
$ok = preg_match(
'/^[A-Z]{4}-d{2}$/', $partno );
# Python
ok = re.match(
'/^[A-Z]{4}-d{2}$/', partno )

26.
Who can read that?

27.
Who can read that?
If you can learn to read
this:
f = (9/5) * c + 32
You can learn to read this:
/^[A-Z]{4}-d{2}$/

28.
Whitespace + comments!
/^[A-Z]{4}-d{2}$/
/ ^ [A-Z]{4} - d{2} $ /x
/
^ # Start of the string
[A-Z]{4} # Four alphas
- # Hyphen
d{2} # Two digits
$ # End of string
/x

29.
Haters like to
point and laugh

30.
Searching
for text

31.
Searching source code
Find all the instances of:
set_user_id
get_user_id
set_user_name
get_user_name

32.
Searching source code
$ grep -R set_user_id .
$ grep -R get_user_id .
$ grep -R set_user_name .
$ grep -R get_user_name .

33.
Searching source code
$ grep -E
'(get|set)_user_(id|name)'
-R .

34.
Searching source code
$ ack '(get|set)_user_(id|name)'
(ack is at https://beyondgrep.com)

35.
Your editor uses regexes

36.
Editors have helpers, too

37.
A different mindset
ok = TRUE # Assume OK
for pos ( 0..3 )
if ( !isalpha( substr(partno,pos,1 ) )
ok = FALSE
if substr(partno,4,1) != '-'
ok = FALSE
for pos ( 5..6 )
if ( !isdigit( substr(partno,pos,1 ) )
ok = FALSE
... or ...
/^[A-Z]{4}-d{2}$/

38.
Concepts

39.
Debugging
How to find programming problems, methodically
narrowing them down to the core cause.

40.
Defensive
programming
What do you do when
"that can never happen" happens?

41.
Testing
Thinking in terms of causing problems
Manual testing
Unit testing
Continuous integration

42.
DRY
Don't Repeat Yourself

43.
Don't Repeat Yourself
"Every piece of knowledge must have a
single, unambiguous, authoritative
representation within a system"
-- Andy Hunt & Dave Thomas
"Cut & paste is a headache in waiting."
-- Andy Lester

44.
Efficiency

45.
Most of the time
"efficiency" doesn't
matter.

46.
Which kind of efficiency are
you talking about anyway?
Run-time speed?
Memory usage?
Disk usage?
Network usage?

47.
Thinking business

48.
Thinking business
You're there to make money for the
company.
Income
Lower costs
Saved time

49.
How do I get my boss
to use Language X?
Show how it will
make money.

50.
How do I get a second
monitor?
Show how it will
make money.

51.
How do I get us to
migrate to the cloud?
Show how it will
make money.

52.
Working with
existing code

53.
This is what you write in school

54.
This is your first project on the job
"Look into ticket #3481"

55.
Working with
existing code
Assignment 5 in CS 200
Write code that does a thing
Assignment 6
Code review on another random student's Assignment 5
Badmouthing their code = instant F
Assignment 7
Extending the code from Assignments 5+6

56.
Written
communication

57.
Telecommuting in
software development
2008 2010 2012 2014 2016 2018 2020

58.
I made up that
meaningless chart,
but the point is...

59.
In everything you do, whether in English
or in a computer language

60.
Teams are
communicating
remotely more

61.
Written communication
Slack
Email
Bug reports
Documentation
Code comments

62.
What can you do to
fill in these gaps?

63.
Two missing textbooks

64.
Work in open source
Working with distributed teams
Source control
Project lifecycle: New features, bugs,
releases, etc
Test-driven development
Written communication

65.
Thank you for your time
Andy Lester, @petdance on Twitter
blog.petdance.com

66.
Two competing
misconceptions of
beginning programmers

67.
You have to have everything
memorized, and if you look
it up you're a loser.
All you have to do is look
things up on the Internet
and use those answers.

68.
Three traits of a
great programmer
Laziness
Impatience
Hubris
-- Larry Wall, creator of patch & Perl

69.
Laziness
The quality that makes you go to great
effort to reduce overall energy expenditure.
It makes you write labor-saving programs
that other people will find useful and
document what you wrote so you don't have
to answer so many questions about it.