php DateTime對象比較

Question

我有簡單的DateTime課程。我正在比較2個DateTime對象，他們沒有正確工作。我試過交換東西，但仍然失敗。當我手動輸入當前日期時，即使日期相同，也會失敗。我必須手動輸入日期。謝謝你的幫助。繼承人的功能：

function dtcompare(){ 
    //I make the date the same as the current 
    //date and it doesnt echo that its equal. 
    $date1 = new DateTime('5/9/2015'); //a date entered 
    $date2 = new DateTime(); //the current date 
    $mdy = 'n/j/Y'; //the format 

    if($date1 == $date2){ 

     echo "d1 == d2"; //This should be echoing 
    } 
    elseif($date1 > $date2){ 

     echo "d1 > d2"; 
    } 
    elseif($date1 < $date2){   

     echo " d1 < d2 "; //but this always echos 
    } 
    } 

我改變了一切，使格式比較，但現在最低的日期回聲，當我把即使是在將來的日期。繼承人發生了什麼：

function dtcompare(){ 
 
    
 
     
 
    $date1 = new DateTime('5/18/2015'); //a future date 
 
    $date2 = new DateTime(); //the current date 
 
    $mdy = 'n/j/Y'; //the format 
 
    
 
    if($date1->format($mdy) == $date2->format($mdy)){ 
 
    
 
     echo "d1 == d2"; 
 
    } 
 
    elseif($date1->format($mdy) > $date2->format($mdy)){ 
 
     //This will echo if the date is in the next month 6/1/2015  
 
     echo "d1 > d2"; 
 
    } 
 
    elseif($date1->format($mdy) < $date2->format($mdy)){   
 
    
 
     //This echos even though it's not 5/18/2015 yet!   
 
     echo $date1->format($mdy)."d1 < d2".$date2->format($mdy); 
 
    } 
 
    }

我一直在玩這個，我得到它通過使用一些雙方的合作。我認爲這不是它應該工作的方式，並且可能會導致現在還沒有意識到的其他日期的問題。繼承人我所做的：

function dtcompare(){ 
 
    
 
    $date1 = new DateTime('5/12/2015'); //a future date 
 
    $date2 = new DateTime(); //the current date 
 
    $mdy = 'n/j/Y'; //the format 
 
    
 
    
 
    //Using the datetime->format for == comparisons and the other 
 
    //way for datetimes greater or less than. This works, but I think this is NOT 
 
    //how this should work though. It feels like a rig for something that 
 
    //should work one way (DateTime->format() comparison) or another (DateTime comparison w.o format) 
 
    if($date1->format($mdy) == $date2->format($mdy)){ 
 
     echo 'date1 and date2 have the same date and time'; 
 
    } 
 
    elseif($date1 > $date2){ 
 
     echo 'date1 > date2 meaning its a later date and time'; 
 
    } 
 
    elseif($date1 < $date2){ 
 
     echo 'date1 < date2 meaning its an earlier date and time'; 
 
    } 
 
}

Answer 1

那麼你定義中，你要比較你的兩個DateTime是你的格式，但你沒有使用過。

只要使用format()與您的格式變量，當您比較兩個日期時間的其他信號和分鐘，只是一切都比較。

if($date1->format($mdy) == $date2->format($mdy)){ 
     //^^^^^^^^^^^^^^ See here, to just compare month, day and year 
    echo "d1 == d2"; //This should be echoing 
} 
elseif($date1->format($mdy) > $date2->format($mdy)){ 

    echo "d1 > d2"; 
} 
elseif($date1->format($mdy) < $date2->format($mdy)){   

    echo " d1 < d2 "; //but this always echos 
} 

編輯：

這應該爲你工作，你必須先格式化你的日期，然後採取時間，像這樣：日期

$mdy = 'n/j/Y'; //the format 
$date1 = strtotime((new DateTime('5/18/2015'))->format($mdy)); 
$date2 = strtotime((new DateTime())->format($mdy)); 


if($date1 == $date2){ 
    echo "d1 == d2"; 
} elseif($date1 > $date2) { 
    echo "d1 > d2"; 
} elseif($date1 < $date2){   
    echo $date1."d1 < d2".$date2; 
} 

Answer 2

使用格式第一和然後比較，因爲你不能比較日期的2個對象直接

使用：

<?php 

    //I make the date the same as the current 
    //date and it doesnt echo that its equal. 
    $date1 = new DateTime('5/9/2015'); //a date entered 
    $date2 = new DateTime(); //the current date 
    $mdy = 'n/j/Y'; //the format 

$date1New = $date1->format('d-m-y'); 
$date2New = $date2->format('d-m-y'); 

////echo '<br> --2'.$date2; 

    if($date1New == $date2New){ 

     echo "d1 == d2"; //This should be echoing 
    } 
    elseif($date1New > $date2New){ 

     echo "d1 > d2"; 
    } 
    elseif($date1New < $date2New){   

     echo " d1 < d2 "; //but this always echos 
    } 

    ?> 

Answer 3

php DateTime已經有能力輸出unixtimestamp。所以你可以像這樣比較：

$early = new DateTime("now"); 
$later = new DateTime("now + 2days"); 

if ($early->format('U') < $later->format('U')) { 
    echo "you'll get this printed"; 
}