Variable names within array. Change their values PHP

Question

I Have a ListNode built that has the following structure:

 class MyNode {
    private  $weight;
    private  $children;
    private  $t1;
    private  $t2;
    private  $t3;
    *** 
    more variables
    ***
    function __constructr($weight, $t1, $t2, $t3, $children = array()) {
        $this->weight = $weight;
        $this->children = $children;
        $this->t1 = $t1;
        $this->t2 = $t2;
        $this->t3 = $t3;
    }

Now I create 5 Nodes that have same data but different weight.

    $n1 = new MyNode(25, 't_1', 't_2', 't_3');
    $n2 = new MyNode(30, 't_1', 't_2', 't_3');
    $n3 = new MyNode(49, 't_1', 't_2', 't_3');
    $n4 = new MyNode(16, 't_1', 't_2', 't_3');
    $n5 = new MyNode(62, 't_1', 't_2', 't_3');

Note that the t1, t2 and t3 can be different but for this 5 nodes they are same. Instead of doing above i want to do the following using some kind of clone function

    $n1 = new MyNode(25, 't_1', 't_2', 't_3');
    $n2 = $n1->clone(array('weight' => 30));
    $n3 = $n2->clone(array('weight' => 49));
    $n4 = $n4->clone(array('weight' => 16));
    $n5 = $n5->clone(array('weight' => 62));

clone function takes array of keys being the variable names inside MyNode that i want to change and their values. so array('weight' => 30) should change $this->weight = 30; Im stuck accessing the variable from array. It should create a new node with all the values being same as its current node but modify only the ones that are in array.

   function clone($changeVariables) {
      -----
   }

Answer 1

Try this:

$obj = clone $this;

foreach ($changeVariables as $field => $val) {
    $obj->{$field} = $val;
}
return $obj;

Answer 2

Observation

• You can not Implement a method or function called clone its a reserved word
• That is not how to clone object in php
• __constructr is wrong and not valid way to set construct in php

Here is what you need :

class MyNode {
    private $weight;
    private $children;
    private $t1;
    private $t2;
    private $t3;

    function __construct($weight, $t1, $t2, $t3, $children = array()) {
        $this->weight = $weight;
        $this->children = $children;
        $this->t1 = $t1;
        $this->t2 = $t2;
        $this->t3 = $t3;
    }

    public function getClone(array $arg) {
        $t = clone $this;
        foreach ( $arg as $k => $v ) {
            $t->{$k} = $v;
        }
        return $t;
    }
}

$n1 = new MyNode(25, 't_1', 't_2', 't_3');
$n2 = $n1->getClone(array(
        'weight' => 30
));

print_r($n1);
print_r($n2);

Output

MyNode Object
(
    [weight:MyNode:private] => 25
    [children:MyNode:private] => Array
        (
        )

    [t1:MyNode:private] => t_1
    [t2:MyNode:private] => t_2
    [t3:MyNode:private] => t_3
)
MyNode Object
(
    [weight:MyNode:private] => 30
    [children:MyNode:private] => Array
        (
        )

    [t1:MyNode:private] => t_1
    [t2:MyNode:private] => t_2
    [t3:MyNode:private] => t_3
)

Answer 3

Variable variables is one solution:

foreach ($changeVariables as $key => $value) {
    $this->{$key} = $value;
}

You could enhance it by checking to see if $this->{$key} exists before allowing it to be set.

http://php.net/manual/en/language.oop5.cloning.php

Overall result would be something like:

function clone($changeVariables) {
    $newObj = clone $this;
    foreach ($changeVariables as $key => $value) {
        $newObj->{$key} = $value;
    }
    return $newObj;
}