当循环遍历对象属性数组时，如何在给定现有键的情况下返回数组值 - When looping through an array of object properties, how can I return an array value given an existing key?

When looping through an array of object properties, how can I return an array value given an existing key?

如果$myObj是：

$myObj = new stdClass();
$myObj = array(1 => 100, 2 => 200, 3 => 300);
echo $myObj[1]; // returns 100, as expected

但当迭代一系列属性时，比如：

$properties_array = array('property_one','property_two');
// and $myObj looks like $myObj->property_one = array(0 => 12345);
foreach ($properties_array as $property) {
    echo $property;
    // returns property name, as expected
    print_r($myObj->$property);
    // returns an array, as expected (ex. Array([0] => 12345))
    echo $myObj->$property[0];
    // expected '12345', instead throws an error: 'Undefined property: stdClass::$myObj'
}

为什么print_r($myObj->$property);会按预期工作，但echo $myObj->$property[0];会抛出错误？

尝试执行echo $myObj->{$property}[0];

使用密钥和值概念

  foreach ($properties_array as $key=>$property) {
       echo $property;//100
       echo $key;//1
  }

在回显std类对象时，无法访问对象