02c04-2.php

介绍PHP5的给类型函数应用

<?php
// Calculating Compound Interest:
// a = the initial amount you are calculating from
// r = the annual percentage rate
// f = the frequency (per year) of compounding
// y = the number of years you wish to calculate this for:
function calc_compound_interest($a, $r, $f, $y) {
	return $a * pow((1 + ($r / $f)), ($f * $y));
}

// Calculate the value of $5000, at 3.25% interest, 
//  compounded daily, for 3 years.   Answer: 5512.0332828079
echo calc_compound_interest(5000, .0325, 365, 3), '<br />';

// Calculate the value of $1000, at 8.5% interest, 
//  compounded monthly, for 6 months.   Answer: 1043.2597499629
echo calc_compound_interest(1000, .085, 12, .5);
?>