php - PHP 2d Array Declaration

Question

I am trying to define a 2d array in php. I have some concept code so you can see the situation:

    class Testing { 
        protected $requiredFieldsByReferenceType = array(
           ['Book']['volume'] => true,
           ['Book']['source'] => true,
           ['Book Section']['volume'] => true,
           ['Book Section']['source'] => true,
           ['Chart or Table']['volume'] => true,
           ['Chart or Table']['source'] => true
        );
        print_r($requiredFieldsByReferenceType);
     }//End Testing

The error that is thrown:

Parse error: syntax error, unexpected '[', expecting ')'

Answer 1

The other answers are good.
The syntax using array() is:

$requiredFieldsByReferenceType = array('Book'=>array('volume' => true,
                                                     'source' => true),
                                       'Book Section'=>array('volume' => true,
                                                             'source' => true)
                                       );

Answer 2

You have to use array() inside the array value declarations too:

protected $myArray = array(
    "Book" => array(
        "item1" => true,
        "item2" => true
    ),
    "Chest" => array(
        "item1" => true,
        "item2" => false
    )
);

Answer 3

$requiredFieldsByReferenceType ['Book']['volume'] = true;
$requiredFieldsByReferenceType ['Book']['source'] = true;
$requiredFieldsByReferenceType ['Book Section']['volume'] = true;

Answer 4

只有在 ONE 语句中分配数组的答案才能在您的上下文中工作（定义类属性），除非您将它们全部放在构造函数中。出于同样的原因，我认为 print_r 不会在没有方法的情况下工作......

Answer 5

$arr1 = array(
    array(value1,value2,value3),
    array(value4,value5,value6),
    array(value7,value8,value9),
);

Answer 6

Another way to do it is by nesting array() functions:

 $requiredFieldsByReferenceType = array(
           'Book' => array('volume' => true,
                                       'source' => true),
           'Book Section' => array('volume' => true,
                                                     'source' => true),
         ...
        );

Answer 7

PHP doesn't do multi-dimensional arrays. You must construct it as arrays of arrays.

protected $myArray = array(
  'Book' => array(
    'item1' => true,
    'item2' => true,
  ),
  'Chest' => array(
  ),
    'item1' => true,
    'item2' => false,
);

Answer 8

Class TestClass {
    protected $myArray = array(
        "Book" => array('item1' => true, 'item2' => false),
        "chest" => array('item1' => true, 'item2' => false),
    );
}

Answer 9

The syntax to define an array is array(key0 => value0, key1 => value1, key2 => value2, ...). Since a two-dimensional array in PHP is just multiple arrays as values in an array, it would look like this:

$myArray =
    array(
        'Book' =>
            array(
                'item1' => true,
                'item2' => true
            ),
        'Chest' =>
            array(
                'item1' => true,
                'item2' => false
            )
    );

Answer 10

Do this instead:

    $myArray = array(
            'book' => array(
                'item1' => true,
                'item2' => true
            ),
            'chest' => array(
                'item1' => true,
                'item2' => true,
            )
        );

By the way you shouldn't initialize your attribues like this. Rather use getters/setters.

class TestClass {
    protected $_myArray;

    public function __construct()
    {
        $this->setMyArray();
    }

    public function setMyArray()
    {
        $this->_myArray = array(
            'book' => array(
                'item1' => true,
                'item2' => true
            ),
            'chest' => array(
                'item1' => true,
                'item2' => true,
            )
        );
    }
}


$foo = new TestClass();
print_r($foo);

Answer 11

It looks like you're mixing styles of appending to an array here.

try

$arr = array(
    'key' => array ('key2' => 'value 1', 'key3' => 'value2'),
    'key12' => array('key4' => 'value4')
);

or

$arr = array();

$arr['key1'] = array();
$arr['key2'] = array();

$arr['key1']['key3'] = 'value1';

(Please note my examples don't produce the same data structure, I was just demonstrating the different methods)