PHP-帶條件開關的Swich case語句

Question

我可以在switch語句中放置條件語句嗎？ ex - switch（$ totaltime < = 13）除了php，其他語言如何兼容？

$totaltime=15; 

switch ($totaltime<=13) { 

case ($totaltime <= 1): 
echo "That was fast!"; 
break; 

case ($totaltime <= 5): 
echo "Not fast!"; 
break; 

case ($totaltime >= 10 && $totaltime<=15): 
echo "That's slooooow"; 
break; 
} 

編輯

$totaltime=12; 
switch (false) { 
case ($totaltime <= 1): 
echo "That was fast!"; 
break; 
case ($totaltime <= 5): 
echo "Not fast!"; 
break; 
case ($totaltime >= 10 && $totaltime<=13): 
echo "That's slooooow"; 
break; 
default: // do nothing break; 
} 

紳士在這種情況下，爲什麼alwyas顯示爲 「真快！」 輸出？

Answer 1

交換機只檢查第一條件是等於第二，這種方式：

switch (CONDITION) { 
    case CONDITION2: 
     echo "CONDITION is equal to CONDITION2"; 
    break; 
} 

所以你要做的它這樣：

switch (true) { 
    case $totaltime <= 1: #This checks if true (first condition) is equal to $totaltime <= 1 (second condition), so if $totaltime is <= 1 (true), is the same as checking true == true. 
     echo "That was fast!"; 
    break; 

    case $totaltime <= 5: 
     echo "Not fast!"; 
    break; 

    case $totaltime >= 10 && $totaltime<=13: 
     echo "That's slooooow"; 
    break; 
} 

而不是我會去if-elseif聲明。乍一看更容易理解：

if ($totaltime <= 1) { 
    echo "That was fast!"; 
} elseif($totaltime <= 5) { 
    echo "Not fast!"; 
} elseif($totaltime >= 10 && $totaltime<=13) { 
    echo "That's slooooow"; 
} 

Answer 2

是的，你可以從PHP的開關文檔：

switch語句是類似於一系列的IF相同的表達式語句。在很多場合，您可能需要將相同的變量（或表達式）與很多不同的值

當案件具有恆定的值進行比較，這就像說，案值==開關值，但你可以有更復雜表達式的情況。

Answer 3

當然可以（除開關內的比較）

$totaltime=12; 

switch (true) { 

case ($totaltime <= 1): 
echo "That was fast!"; 
break; 

case ($totaltime <= 5): 
echo "Not fast!"; 
break; 

case ($totaltime >= 10 && $totaltime<=13): 
echo "That's slooooow"; 
break; 

default: 
// do nothing 
break; 
}