Ds\Map::put

(PECL ds >= 1.0.0)

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

Descrição

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

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

Nota:
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.

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

Cuidado

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.

Parâmetros

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

Valor Retornado

Não há valor retornado.

Exemplos

Exemplo #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);
?>

O exemplo acima irá imprimir algo similar 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
        )

)

Exemplo #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);
?>

O exemplo acima irá imprimir algo similar 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)
  }
}