Respuesta :
Answer:
display_result.php
<?php
// get the data from the form
$investment = filter_input(INPUT_POST, 'investment',
FILTER_VALIDATE_FLOAT);
$interest_rate = filter_input(INPUT_POST, 'interest_rate',
FILTER_VALIDATE_FLOAT);
$years = filter_input(INPUT_POST, 'years',
FILTER_VALIDATE_INT);
// validate investment
if ($investment === FALSE )
{
$error_message = 'Investment must be a valid number.';
}
else if ( $investment <= 0 )
{
$error_message = 'Investment must be greater than zero.';
// validate interest rate
}
else if ( $interest_rate === FALSE )
{
$error_message = 'Interest rate must be a valid number.';
}
else if ( $interest_rate <= 0 )
{
$error_message = 'Interest rate must be greater than zero.';
// validate years
}
else if ( $interest_rate >= 15 )
{
$error_message = 'Interest rate must be less than or equal to 15.';
// validate years
}
else if ( $years === FALSE ) {
$error_message = 'Years must be a valid whole number.';
}
else if ( $years <= 0 )
{
$error_message = 'Years must be greater than zero.';
}
else if ( $years > 30 )
{
$error_message = 'Years must be less than 31.';
// set error message to empty string if no invalid entries
}
else
{
$error_message = '';
}
// if an error message exists, go to the index page
if ($error_message != '')
{
include('index1.php');
exit();
}
// calculate the future value
$future_value = $investment;
if (isset($_POST["monthly"]))
{ //compound monthly
$compounded_monthly="Yes";
$months=$years*12;
$monthly_rate = $interest_rate / 12;
for ($i=1;$i<=$months;$i++)
{
$future_value =$future_value + ($future_value * $monthly_rate * .01);
}
// apply currency and percent formatting
}
else
{
for ($i = 1; $i <= $years; $i++)
{
$future_value =$future_value + ($future_value * $interest_rate * .01);
}
}
$investment_f = '
