Question

我的切换案例允许查找具有两个特定值的表。这就是我想做的事情：

foreach ($array as $key => $value) {
   switch($value) {
             case "C": 
             case "D":
     //Take all key from "C" until I come across a second value "C" or "D"
   }
}

以下是一个例子：

$array =
 (
      [53] => q
      [61] => f
      [74] => s
      [87] => C
      [19] => D
      [101] => e
      [22] => C
      [13] => h
 )

结果：“87 19 101”

Answer 1

首先要指出你的代码是你的关联数组的语法有错误。然后你可以使用我在下面显示的方式

<?php

$array = array (
      "53" => "q",
      "61" => "f",
      "74" => "s",
      "87" => "C",
      "19" => "D",
      "101" => "e",
      "22" => "C",
      "13" => "h");


 foreach ($array as $key => $value) {
    switch($value) {
        case "C":
        case "D":
        case "e":
            echo $key . ' ';
        break;
    }
}

结果：87 19 101 22

由于我的回答为您提供了另外的额外输出，因此您只能获取前三项，或者您可以编写重复过滤脚本，如Lionel Chan的回答所示。

Answer 2

这是一个奇怪的逻辑，但这应该有效：

//Triggers are the flags that trigger opening or close of filters
$triggers = array('C', 'D');
$filtered = [];
$stack = [];

foreach($array as $k => $v) {

    //If the trigger is opened and I see it again, break the loop
    if (in_array($v, $stack)) {
        break;
    }

    //If we sees the trigger OR the stack is not empty (we are opened)
    //continuously pull the keys out
    if (in_array($v, $triggers) || !empty($stack)) {
        $stack[] = $v;
        $filtered[] = $k;
    }
}

此输出为

Array
(
  [0] => 87
  [1] => 19
  [2] => 101
)

如何在PHP中使用特定值的键？

2 个答案: