Ds\Map::put

(PECL ds >= 1.0.0)

Ds\Map::put — Associates a key with a value

Description

public Ds\Map::put(mixed $key, mixed $value): void

Associates a key with a value, overwriting a previous association if one exists.

Note:
Keys of type object are supported. If an object implements Ds\Hashable, equality will be determined by the object's equals function. If an object does not implement Ds\Hashable, objects must be references to the same instance to be considered equal.

Note:
You can also use array syntax to associate values by key, eg. $map["key"] = $value.

Attention

Be careful when using array syntax. Scalar keys will be coerced to integers by the engine. For example, $map["1"] will attempt to access int(1), while $map->get("1") will correctly look up the string key.

See Arrays.

Liste de paramètres

key: The key to associate the value with.
value: The value to be associated with the key.

Valeurs de retour

Aucune valeur n'est retournée.

Exemples

Exemple #1 Ds\Map::put() example

<?php
$map = new \Ds\Map();

$map->put("a", 1);
$map->put("b", 2);
$map->put("c", 3);

print_r($map);
?>

Résultat de l'exemple ci-dessus est similaire à :

Ds\Map Object
(
    [0] => Ds\Pair Object
        (
            [key] => a
            [value] => 1
        )

    [1] => Ds\Pair Object
        (
            [key] => b
            [value] => 2
        )

    [2] => Ds\Pair Object
        (
            [key] => c
            [value] => 3
        )

)

Exemple #2 Ds\Map::put() example using objects as keys

<?php
class HashableObject implements \Ds\Hashable
{
    /**
     * An arbitrary value to use as the hash value. Does not define equality.
     */
    private $value;

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

    public function hash()
    {
        return $this->value;
    }

    public function equals($obj): bool
    {
        return $this->value === $obj->value;
    }
}

$map = new \Ds\Map();

$obj = new \ArrayIterator([]);

// Using the same instance multiple times will overwrite the previous value.
$map->put($obj, 1);
$map->put($obj, 2);

// Using multiple instances of the same object will create new associations.
$map->put(new \stdClass(), 3);
$map->put(new \stdClass(), 4);

// Using multiple instances of equal hashable objects will overwrite previous values.
$map->put(new \HashableObject(1), 5);
$map->put(new \HashableObject(1), 6);
$map->put(new \HashableObject(2), 7);
$map->put(new \HashableObject(2), 8);

var_dump($map);
?>

Résultat de l'exemple ci-dessus est similaire à :

object(Ds\Map)#1 (5) {
  [0]=>
  object(Ds\Pair)#7 (2) {
    ["key"]=>
    object(ArrayIterator)#2 (1) {
      ["storage":"ArrayIterator":private]=>
      array(0) {
      }
    }
    ["value"]=>
    int(2)
  }
  [1]=>
  object(Ds\Pair)#8 (2) {
    ["key"]=>
    object(stdClass)#3 (0) {
    }
    ["value"]=>
    int(3)
  }
  [2]=>
  object(Ds\Pair)#9 (2) {
    ["key"]=>
    object(stdClass)#4 (0) {
    }
    ["value"]=>
    int(4)
  }
  [3]=>
  object(Ds\Pair)#10 (2) {
    ["key"]=>
    object(HashableObject)#5 (1) {
      ["value":"HashableObject":private]=>
      int(1)
    }
    ["value"]=>
    int(6)
  }
  [4]=>
  object(Ds\Pair)#11 (2) {
    ["key"]=>
    object(HashableObject)#6 (1) {
      ["value":"HashableObject":private]=>
      int(2)
    }
    ["value"]=>
    int(8)
  }
}

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