Strategy-like Pattern in PHP
Today, I had some time to write a little program while I was watching people work on the infrastructure at the office. I wrote up a couple of functions that calculated the n-th Fibonacci number, and wanted to display the sequence of the first 100 numbers as they were calculated by these functions. At first, I had something like the following:
<?php
for( $i = 1; $i < = 100; ++$i )
{
printf( "%d ", fibonacci_tabularized( $i ) );
}
for( $i = 1; $i < = 100; ++$i )
{
printf( "%d, ", fibonacci_iterative( $i ) );
}
for( $i = 1; $i < = 100; ++$i )
{
printf( "%d, ", fibonacci_recursive( $i ) );
}
?>
I quickly realized how horrible it was. That sure is a lot of duplicate code! So, I ended up rewriting it so that it looks like this:
<?php
function print_fibonacci_sequence( $strategy, $n )
{
for( $i = 1; $i < = $n; ++$i )
{
printf( "%d, ", $strategy($n) );
}
printf( "\r\n" );
}
$strategies = array(
"fibonacci_tabularized",
"fibonacci_iterative",
"fibonacci_recursive"
);
foreach( $strategies as $strategy )
{
print_fibonacci_sequence( $strategy, 100 );
}
?>