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Ds\Map::put

(PECL ds >= 1.0.0)

Ds\Map::putAssociates a key with a value

Опис

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

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

Зауваження:

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.

Зауваження:

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

Застереження

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.

Параметри

key

The key to associate the value with.

value

The value to be associated with the key.

Значення, що повертаються

Не повертає значень.

Приклади

Приклад #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);
?>

Поданий вище приклад виведе щось схоже на:

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
        )

)

Приклад #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);
?>

Поданий вище приклад виведе щось схоже на:

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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