英文:
PHP can i access array key with variable variables?
问题
我有一个包含一些信息的数组，但我尝试以可变变量的方式访问数组，但我不知道如何实现，因为PHP解释整个字符串是一个变量而不是带有关联键的变量。我的示例代码：$myArrayWithData = ["info" => 1];$myvarvarArray = "myArrayWithData['info']";print_r($$myvarvarArray);
期望行为：
1
实际行为：
Notice: Undefined variable: myArrayWithData['info']
我不想硬编码索引，因为我试图创建一个Twig函数，通过字符串创建数组索引路径，而我无法预测数组键。
$myvarvarArray = "myArrayWithData";print_r($$myvarvarArray["info"]); #硬编码的索引
编辑：我的函数可以添加多个索引
/*** 向您的Twig数组中添加一个值，而不是使用合并** @param $object 要设置新值的数组或对象（公共访问）* @param string $context 要设置值的对象完整路径，例如 "children.grandchildren.info"* @param $value 要插入的值**/public function enhancedMerge($object, $contexts, $value){$contexts = explode('.', $contexts);$newObject = $object;$path = '';foreach($contexts as $key => $context){$objectWithPath = 'newObject' . $path;$contextIsArray = is_array(${$objectWithPath}) ? true : false;if($contextIsArray){$path .= "['" . $context . "']";}else{$path .= "->" . $context;}}$objectWithPath = $newObject . $path;$$objectWithPath = $value;return $$newObject;}
英文:
i have an array with some info but i am trying to implement a way to access array dynamically with variable variables but i have no idea how, because php interprets that the whole string is a variable and not a variable with an associative key.
my example code:
$myArrayWithData = ["info" => 1];$myvarvarArray = "myArrayWithData['info']";print_r($$myvarvarArray);
expected behavior:
1
Actual Behavior:
`"Notice: Undefined variable: myArrayWithData['info']"`
i don want to hardcode indexes because i am trying to create a twig function that creates the array index path by a string and i am not able to predict the array Keys.
$myvarvarArray = "myArrayWithData"print_r($$myvarvarArray["info"]); #hardcoded index
edit: my function can add more than 1 index
/*** add a value to your twig array instead of using merge** @param $object Array or object(public access) to set a new value* @param string $context object complete path where value will be setted example "children.grandchildren.info"* @param $value value to be inserted**/public function enhancedMerge($object, $contexts, $value){$contexts = explode('.', $contexts);$newObject = $object;$path = '';foreach($contexts as $key => $context){$objectWithPath = 'newObject' . $path;$contextIsArray = is_array(${$objectWithPath}) ? true : false;if($contextIsArray){$path .= "['" . $context . "']";}else{$path .= "->" . $context;}}$objectWithPath = $newObject . $path;$$objectWithPath = $value;return $$newObject;}
答案1
得分: 1
不可以使用变量变量来访问数组键。
然而，我们可以使用引用变量来访问它们，就像这个答案中所示。
我的函数现在向数组"twigs"添加值
public function enhancedMerge($object, $contexts, $value){$contexts = explode('.', $contexts);$elemCount = count($contexts);$current = &$object;foreach ($contexts as $key => $context) {if (is_array($current)) {$current = &$current[$context];} elseif ($key != $elemCount-1) {$current = &$current->$context;}}$backup = $current;$current = $value; #设置新值并通过引用修改$objectreturn $object;}
英文:
Can I access array key with variable variables?
Short answer: No.
However, we can access them using reference variables like this answer.
My function now adds values to array twigs
public function enhancedMerge($object, $contexts, $value){$contexts = explode('.', $contexts);$elemCount = count($contexts);$current = &$object;foreach ($contexts as $key => $context) {if (is_array($current)) {$current = &$current[$context];} elseif ($key != $elemCount-1) {$current = &$current->$context;}}$backup = $current;$current = $value; #set new value and modify $object by referencereturn $object;}
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