Ds\Map::put
(PECL ds >= 1.0.0)
Ds\Map::put — Associates a key with a value
說明
Associates a key with a value,
overwriting a previous association if one exists.
注意:
Keys of type object are supported. If an object implements Ds\Hashable, equality will be determined by the object's
equalsfunction. If an object does not implement Ds\Hashable, objects must be references to the same instance to be considered equal.
注意:
You can also use array syntax to associate values by key, eg.
$map["key"] = $value.
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.
參數
-
key -
The key to associate the value with.
-
value -
The value to be associated with the key.
返回值
沒有返回值。
範例
示例 #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);
?>
以上例程的輸出類似於：
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
)
)
示例 #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);
?>
以上例程的輸出類似於：
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)
}
}