function calculateCompoundInterest($principal, $rate, $years) {
// Validate input: all values must be non-negative
if ($principal < 0 || $rate < 0 || $years < 0) {
echo "Error: Principal, rate, and years must be non-negative values.\n";
return -1;
}
// Calculate total amount using the compound interest formula
$amount = $principal * pow(1 + $rate / 100, $years);
// Return compound interest (total amount - principal)
return $amount - $principal;
}
$principal = 100000;
$rate = 3.5;
$years = 5;
$compoundInterest = calculateCompoundInterest($principal, $rate, $years);
if ($compoundInterest >= 0) {
echo "Principal Amount: " . number_format($principal, 2) . "\n";
echo "Annual Interest Rate: " . number_format($rate, 2) . "%\n";
echo "Years: " . number_format($years, 2) . "\n";
echo "Compound Interest: " . number_format($compoundInterest, 2) . "\n";
echo "Total Amount: " . number_format($principal + $compoundInterest, 2) . "\n";
}
/*
run:
Principal Amount: 100,000.00
Annual Interest Rate: 3.50%
Years: 5.00
Compound Interest: 18,768.63
Total Amount: 118,768.63
*/
