How do you clone an object in php?
Hunain Tahir Show
One cannot create a copy constructor in PHP as overloading of
methods is not allowed. But to get a full replica of an object, we can use a keyword Syntax
The method Example
How to use keyword `clone` in PHP Explanation
Example of __clone()Now let’s see how to add the
Changing properties after cloning Explanation
ConclusionYou can use the keyword
CONTRIBUTOR Hunain TahirCopyright ©2022 Educative, Inc. All rights reserved Home / Copying an object in PHP with clone Objects in PHP are assigned by reference, so copying an object with the = operator will result in a second variable referencing the same object and not an actual copy. Enter PHP’s clone function which creates a shallow copy of the object. Using = to copy an object copies the reference onlyTo illustrate how PHP only makes a reference to the original object using the = operator look at the following example. (Note that I’ve made the = assignment red in the example). class foo {
public $bar;
}
$foo = new foo();
$foo->bar = 'baz';
$foo2 = $foo;
$foo2->bar = 'bat';
echo $foo->bar;
echo $foo2->bar;
Both echo lines at the end of the example will echo "bat" and not "baz" and "bat", because $foo2 is a reference to $foo and accessing properties and calling methods for $foo2 is actually referring to those properties and methods of $foo. Using clone to copy and object copies the objectUsing the same example, but using clone instead to copy the object will result in a copy of the original object. Changing properties and calling methods will do so to the copied object and not the original. The only difference between the above example and this one is "=" becomes "clone" which is highlighted in red in both examples. class foo {
public $bar;
}
$foo = new foo();
$foo->bar = 'baz';
$foo2 = clone $foo;
$foo2->bar = 'bat';
echo $foo->bar . "n";
echo $foo2->bar . "n";
The second example outputs "baz" and then "bat". Shallow copyCloning an object creates a "shallow" copy of the original object. What this means is that any properties that are references to other variables will remain references to those variables and not copies themselves. The __clone methodIf the object contains a __clone method it will be called when the object is cloned. It must be a publicly accessible function and cannot be called directly otherwise PHP will end with a fatal error.You wouldn’t actualy echo output when cloning, but if the object was cloned in the example below, it would echo out "i’ve been cloned". class foo { public $bar; public function __clone() { echo "i've been cloned"; } } If you attempt to call the __clone() method yourself, the following error will occur: Fatal error: Cannot call __clone() method on objects - use 'clone $obj' instead in ... Does PHP support object cloning?The value of the object variable can be copied to another variable in PHP by using object cloning. In PHP, a shallow copy of the object can be created by using the keyword clone, and a deep copy of the object can be created by using the method __clone().
What is clone () method?clone() method in Java
Object class has a clone method which can be used to copy the values of an object without any side-effect. Assignment operator has a side-effect that when a reference is assigned to another reference then a new object is not created and both the reference point to the same object.
How do you create copy of an object?To copy an object in JavaScript, you have three options:. Use the spread ( ... ) syntax.. Use the Object. assign() method.. Use the JSON. stringify() and JSON. parse() methods.. What is deep copy and shallow copy in PHP?Shallow copy: Copies the member values from one object into another. Deep Copy: Copies the member values from one object into another. Any pointer objects are duplicated and Deep Copied.
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