php - 如何在 php 数组中添加条件？

Question

这是数组

$anArray = array(
   "theFirstItem" => "a first item",
   if(True){
     "conditionalItem" => "it may appear base on the condition",
   }
   "theLastItem"  => "the last item"

);

但是我得到了 PHP Parse 错误，为什么我可以在数组中添加一个条件，发生了什么？？:

PHP Parse error:  syntax error, unexpected T_IF, expecting ')'

Answer 1

很遗憾，这根本不可能。

如果有该项目但具有 NULL 值是可以的，使用这个:

$anArray = array(
   "theFirstItem" => "a first item",
   "conditionalItem" => $condition ? "it may appear base on the condition" : NULL,
   "theLastItem"  => "the last item"
);

否则你必须这样做:

$anArray = array(
   "theFirstItem" => "a first item",
   "theLastItem"  => "the last item"
);

if($condition) {
   $anArray['conditionalItem'] = "it may appear base on the condition";
}

如果顺序很重要，那就更丑了:

$anArray = array("theFirstItem" => "a first item");
if($condition) {
   $anArray['conditionalItem'] = "it may appear base on the condition";
}
$anArray['theLastItem'] = "the last item";

不过，你可以让它更易读:

$anArray = array();
$anArray['theFirstItem'] = "a first item";
if($condition) {
   $anArray['conditionalItem'] = "it may appear base on the condition";
}
$anArray['theLastItem'] = "the last item";