- implode: documentation ( source)
<?php
namespace JoshDiFabio;
interface RomanNumeralGeneratorInterface
{
/**
* @param int $number
* @return string
* @throws \InvalidArgumentException Argument not an integer or out of range
* @author Josh Di Fabio <joshdifabio@hotmail.com>
*/
public function generate($number);
}
class RomanNumeral
{
const ONE = 'I';
const FIVE = 'V';
const TEN = 'X';
const FIFTY = 'L';
const ONE_HUNDRED = 'C';
const FIVE_HUNDRED = 'D';
const ONE_THOUSAND = 'M';
}
class RomanNumeralGenerator implements RomanNumeralGeneratorInterface
{
/**
* @var array
* @author Josh Di Fabio <joshdifabio@hotmail.com>
*/
private $_integerNumeralMap = array(
1000 => RomanNumeral::ONE_THOUSAND,
500 => RomanNumeral::FIVE_HUNDRED,
100 => RomanNumeral::ONE_HUNDRED,
50 => RomanNumeral::FIFTY,
10 => RomanNumeral::TEN,
5 => RomanNumeral::FIVE,
1 => RomanNumeral::ONE,
);
/**
* @param int $number
* @return string
* @throws \InvalidArgumentException Argument not an integer or out of range
* @author Josh Di Fabio <joshdifabio@hotmail.com>
*/
public function generate($number)
{
if (!is_integer($number)) {
throw new \InvalidArgumentException('Provided argument is not an integer.');
}
if (1 > $number || 3999 < $number) {
throw new \InvalidArgumentException(
'The provided number is not within the allowed range of 1 to 3999.');
}
$numerals = array();
while (0 < $number) {
foreach ($this->_integerNumeralMap as $_integer => $_numeral) {
if ($number >= $_integer) {
$numerals[] = $_numeral;
$number -= $_integer;
break;
}
}
}
return implode('', $numerals);
}
}
$generator = new RomanNumeralGenerator;
echo $generator->generate(312);