02c03-1.php

来自「介绍PHP5的给类型函数应用」· PHP 代码 · 共 41 行

<?php
// A function to return the Roman Numeral, given an integer
function romanize($num) {
	// Make sure that we only use the integer portion of the value
	$n = intval($num);
	$result = '';

	// Declare a lookup array that we will use to traverse the number:
	$lookup = array('M' => 1000, 'CM' => 900, 'D' => 500, 'CD' => 400,
					'C' => 100, 'XC' => 90, 'L' => 50, 'XL' => 40, 
					'X' => 10, 'IX' => 9, 'V' => 5, 'IV' => 4, 'I' => 1);

	// Now, let's work our way through the values, building the string
	//  as we go:  At each step, divide out the maximum matches at this
	//  level, echo out that many characters and then drop the number 
	//  down to the remainder and repeat:
	foreach ($lookup as $roman => $value) {
		// Determine the number of matches:
		$matches = intval($n / $value);

		// Store that many characters:
		$result .= str_repeat($roman, $matches);

		// Substract that from the number
		$n = $n % $value;
	}
	
	// The Roman numeral should be built, return it
	return $result;	
}

// Convert various numbers to Roman Numerals and echo them. Should display:
// 2005 = MMV
// 1999 = MCMXCIX
// 42 = XLII
echo '<pre>';
echo "\n 2005 = ", romanize(2005);
echo "\n 1999 = ", romanize(1999);
echo "\n 42 = ", romanize(42);
echo '</pre>';
?>