3. Keywords
A keyword is a word or identifier that has a particular
meaning in a programming language
In many languages keywords are reserved words that
identify a syntactic form.They cannot be used as the
names of variables or functions.
Words used in control flow, like if/then/else are keywords.
Operators: + - == <= and or
Conditionals: if elseif else
Looping:
while do for foreach as
Functions: function return
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4. Keyword Examples
/**
* Reduce any integer to an arbitrary number between 1 and 5
* @param integer $argument greater than 0
* @return integer between 1 and 5
*/
function reduce( $argument ) {
if ( $argument >= 0 and $argument < 5 )
return $argument + 1;
if ( $argument > 5 and $argument <= 10 )
return $argument - 5;
if ( $argument == 5 )
return $argument;
}
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return reduce( (integer) $argument / 2 );
5. Rules of the Code Dojo
Pair Programming:
Pilot-Copilot
One person is the pilot and does the typing
One person is the copilot and tries to talk the solution out
Everyone else is passengers (quiet while flying!)
Timed for X minutes, then:
The pilot becomes a passenger, the copilot becomes the pilot, a
passenger becomes the new copilot
Repeat until the problem is solved, everyone has been pilot and
copilot, or we run out of time
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6. Rules of the Dojo cont.
Test Driven Development:
Red-Green-Refactor
Red: the pilot cannot write any production code until there is at
least one failing test
Green: the pilot should only write production code that attempts
to satisfy the current failing tests, save and rerun frequently
Refactor: Once all tests are passing, look for opportunities to
simplify or improve readability before moving on
Don't talk while Red:
Only the pair can talk while the timer is running
Allow the pair time to figure out the next steps on their own
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7. Dojo Assignment
Write a set of functions that all accept exactly two
parameters and provide the functionality of a basic
calculator: addition, subtraction, multiplication and
division. Use simple assertion tests to develop in a test
driven manner:
assert( 'add(1,1) == 2' );
assert( 'sub(4,2) == 2' );
Ensure that your test covers positive and negative
numbers for all operations and multiplication or division
by zero. The program should never produce a Fatal Error,
so handle error conditions internally
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8. Retrospective
What did we do well that we should try to do again?
What did we do poorly that we should try to correct?
Did we achieve our goals and why or why not?
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