我该如何在php中编写这个特定条件？

Question

The Challenge is:

• If the book is returned on or before the expected return date, no fine will be charged (i.e.: fine=0).
• If the book is returned after the expected return day but still within the same calendar month and year as the expected return date, fine=15 Hackos × (the number of days late).
• If the book is returned after the expected return month but still within the same calendar year as the expected return date, the fine=500 Hackos × (the number of months late).
• If the book is returned after the calendar year in which it was expected, there is a fixed fine of 10000 Hackos.

And My code is:

<?php
$expectedDay   = "6";
$expectedMonth = "6";
$expectedYear  = "2015";

$returnDay     = "9";
$returnMonth   = "6";
$returnYear    = "2015";
if ($expectedDay >= $returnDay && $expectedMonth >= $returnMonth && $expectedYear >= $returnYear) {
    echo "Fine = 0";
}elseif ($expectedDay < $returnDay && $expectedMonth == $returnMonth && $expectedYear == $returnYear) {
    $fine = 15 * ($returnDay-$expectedDay);
    echo "Fine = ".$fine;
}elseif (($expectedDay <= $returnDay || $expectedDay >= $returnDay) && $expectedMonth < $returnMonth && $expectedYear == $returnYear) {
    $fine = 500 * ($returnMonth-$expectedMonth);
    echo "Fine = ".$fine;
}else{
    echo "Fine = 1000";
}

?> 

Its running well.But failed when the input is:

$expectedDay   = "28";
$expectedMonth = "2";
$expectedYear  = "2015";

$returnDay     = "15";
$returnMonth   = "4";
$returnYear    = "2015";

How i write for this condition? Thanks in advanced.

Note: This is not a business logic.It is just Practice purposes.I am beginner in PHP.

Answer 1

You do not have to compare dates when the month condition is checked.

<?php
$expectedDay   = "6";
$expectedMonth = "6";
$expectedYear  = "2015";

$returnDay     = "9";
$returnMonth   = "6";
$returnYear    = "2015";
$returnDate = new DateTime($returnDay.'-'.$returnMonth.'-'.$returnYear);
$expectedDate = new DateTime($expectedDay.'-'.$expectedMonth.'-'.$expectedYear);

if ($returnDate <= $expectedDate) {
    echo "Fine = 0";
}elseif ($expectedDay < $returnDay && $expectedMonth == $returnMonth && $expectedYear == $returnYear) {
    $fine = 15 * ($returnDay-$expectedDay);
    echo "Fine = ".$fine;
}elseif ($expectedMonth < $returnMonth && $expectedYear == $returnYear) {
    $fine = 500 * ($returnMonth-$expectedMonth);
    echo "Fine = ".$fine;
}else{
    echo "Fine = 1000";
}

?> 

Try that.