Question

我正在从API中提取变量字符串Rarity。

然后，我需要根据收到的内容缩短此字符串。所以我使用了一个很大的if / else块：

if($rarity == "Common"){
    $rarestring = "(C)";
}else if($rarity == "Rare"){
    $rarestring = "(R)";
}else if($rarity == "Super Rare"){
    $rarestring = "(SR)";
}else if($rarity == "Holofoil Rare"){
    $rarestring = "(HFR)";
}else if($rarity == "Ultra Rare"){
    $rarestring = "(UR)";
}else if($rarity == "Ultimate Rare"){
    $rarestring = "(UtR)";
}else if($rarity == "Secret Rare"){
    $rarestring = "(ScR)";
}else if($rarity == "Ultra Secret Rare"){
    $rarestring = "(UScR)";
}else if($rarity == "Secret Ultra Rare"){
    $rarestring = "(SCuR)";
}else if($rarity == "Prismatic Secret Rare"){
    $rarestring = "(PScR)";
}else if($rarity == "Ghost Rare"){
    $rarestring = "(GR)";
}else if($rarity == "Parallel Rare"){
    $rarestring = "(PR)";
}else if($rarity == "Parallel Common"){
    $rarestring = "(PC)";
}else if($rarity == "Super Parallel Rare"){
    $rarestring = "(SPR)";
}else if($rarity == "Ultra Parallel Rare "){
    $rarestring = "(UPR)";
}else if($rarity == "Duel Terminal Parallel Common"){
    $rarestring = "(DPC)";
}else if($rarity == "Duel Terminal Rare Parallel Rare"){
    $rarestring = "(DRPR)";
}else if($rarity == "Duel Terminal Super Parallel Rare"){
    $rarestring = "(DSPR)";
}else if($rarity == "Duel Terminal Ultra Parallel Rare"){
    $rarestring = "(DUPR)";
}else if($rarity == "Duel Terminal Secret Parallel Rare"){
    $rarestring = "(DScPR)";
}else if($rarity == "Gold Rare"){
    $rarestring = "(GUR)";
}

我不禁觉得这不是最佳选择。我知道，通常情况下，性能提升不是很重要，但我觉得这可能是学习并可能做得更好的好机会。

我认为我可以将所有稀有物放入一个数组中，但是我仍然遇到相同的问题，需要比较然后缩短。

Answer 1

是的，使用数组映射：

$options = [
  'Common' => '(C)',
  'Rare' => '(R)',
];
//...
if (!isset($options[$rarity])) {
  throw new Exception('Unknown rarity ' . $rarity);
}
$rarestring = $options[$rarity];

或者您可以使用switch构造：

switch($rarity) {
  case 'Common': $rarestring = '(C)'; break;
  case 'Rare': $rarestring = '(R)'; break;
  default: throw new Exception('Unknown rarity ' . $rarity);
}

编辑：

对于那些可能会读到这的人来说，这是未来。与许多人所说的相反，该数组总是更好，这两种方法（数组与切换）之间存在真正的区别，不同之处在于它是用代码编写的。

Switch的行为非常类似于elseif序列-它允许每种情况执行一个代码块，而最后一种情况花费的时间最多，因为以前的所有情况都必须与针进行比较（$ rarity in上面的情况）。时间复杂度O（n）。内存复杂度O（1）。

另一方面，当每种情况都应返回预定义的值时，数组仅允许用例。并且在PHP数组中实现为哈希表，其中密钥查找t的时间复杂度为O（1）

Answer 2

您可以这样做，

$arr = [
    "Common"                             => "(C)",
    "Rare"                               => "(R)",
    "Super Rare"                         => "(SR)",
    "Holofoil Rare"                      => "(HFR)",
    "Ultra Rare"                         => "(UR)",
    "Ultimate Rare"                      => "(UtR)",
    "Secret Rare"                        => "(ScR)",
    "Ultra Secret Rare"                  => "(UScR)",
    "Secret Ultra Rare"                  => "(SCuR)",
    "Prismatic Secret Rare"              => "(PScR)",
    "Ghost Rare"                         => "(GR)",
    "Parallel Rare"                      => "(PR)",
    "Parallel Common"                    => "(PC)",
    "Super Parallel Rare"                => "(SPR)",
    "Ultra Parallel Rare "               => "(UPR)",
    "Duel Terminal Parallel Common"      => "(DPC)",
    "Duel Terminal Rare Parallel Rare"   => "(DRPR)",
    "Duel Terminal Super Parallel Rare"  => "(DSPR)",
    "Duel Terminal Ultra Parallel Rare"  => "(DUPR)",
    "Duel Terminal Secret Parallel Rare" => "(DScPR)",
    "Gold Rare"                          => "(GUR)",
];
echo ($arr[$rarity] ?? 'nothing');

您无需为此编写任何开关或if-else块。

是否存在将字符串应用于if / else链以外的变量的最佳方法

2 个答案: