PHP 函数不从多维数组返回值

Question

我一直在研究一个调色板系统，其中多维数组包含不同的调色板。前任：

$palette['1']['borderColor'] = "black";
$palette['2']['borderColor'] = "white";

我有一个函数，它在调用时应该返回一个调色板项目，但由于某种原因它没有返回任何内容。相反，它说"未定义的变量：调色板"EX：

$palette['1'] = array(
    "borderColor"=> "#222222",
    "divColor1"=> "#00f2ff",
    "divColor2"=> "#222222",
    "headerColor"=> "rgba(38, 38, 38, 0.5)",
    "color1"=> "#00f2ff",
    "color2"=> "#e9ffdd"
  );
function getItem($number, $item) {
  return $palette[$number][$item];
}
$borderColor = getItem('1', 'borderColor');
echo "borderColor is> " . $borderColor . " <.";
//returns "borderColor is>  <."

有什么建议吗？

Answer 1

您编写的函数没有实际的调色板值。只需将所需的调色板传递到函数中即可。

$palette['1'] = array(
    "borderColor"=> "#222222",
    "divColor1"=> "#00f2ff",
    "divColor2"=> "#222222",
    "headerColor"=> "rgba(38, 38, 38, 0.5)",
    "color1"=> "#00f2ff",
    "color2"=> "#e9ffdd"
  );
function getItem($palette, $number, $item) {
  return $palette[$number][$item];
}
$borderColor = getItem($palette,'1', 'borderColor');
echo "borderColor is> " . $borderColor . " <.";

执行此操作的另一种方法是创建一个简单的类，您可以在其中调用调色板。

class Palette {
  public function __construct($palette){
  $this->borderColor  = $palette['borderColor'];
  $this->divColor1    = $palette['divColor1'];
  $this->divColor2    = $palette['divColor2'];
  $this->headerColor  = $palette['headerColor'];
  $this->color1       = $palette['color1'];
  $this->color2       = $palette['color2'];
  }

}
$palette['1'] = array(
    "borderColor"=> "#222222",
    "divColor1"=> "#00f2ff",
    "divColor2"=> "#222222",
    "headerColor"=> "rgba(38, 38, 38, 0.5)",
    "color1"=> "#00f2ff",
    "color2"=> "#e9ffdd"
  );
$black = new Palette($palette['1']);
$white = new Palette($palette['2']);
echo $black->borderColor;
echo $white->borderColor;

Answer 2

实际上在你的getItem函数中，变量$palette不可用，所以你必须在getItem函数上传递它，或者只是在函数的$palette变量上添加全局关键字。

方式1：

function getItem($palette, $number, $item) {
  return $palette[$number][$item];
}
$borderColor = getItem($palette,'1', 'borderColor');

方式2：

function getItem($number, $item) {
  global $palette; // it will be available here
  return $palette[$number][$item];
}
$borderColor = getItem('1', 'borderColor');

演示 https://eval.in/988491