An object copy is created by using the clone keyword (which calls the object’s __clone() method if possible). An object’s __clone() method cannot be called directly. When an object is cloned, PHP will perform a shallow copy of all of the object’s properties. Any properties that are references to other variables will remain references.
Syntax:
$copy_object_name = clone $object_to_be_copied
Program 1: Program to create copy of an object.
php
<?php// Program to create copy of an object// Creating classclass GFG { public $data1; public $data2; public $data3;}// Creating object$obj = new GFG();// Creating clone or copy of object$copy = clone $obj;// Set values of $obj object$obj->data1 = "Geeks";$obj->data2 = "for";$obj->data3 = "Geeks";// Set values of copied object$copy->data1 = "Computer ";$copy->data2 = "science ";$copy->data3 = "portal";// Print values of $obj objectecho "$obj->data1$obj->data2$obj->data3\n";// Print values of $copy objectecho "$copy->data1$copy->data2$copy->data3\n";?> |
Output:
neveropen Computer science portal
Example 2: Below program distinguishes clone from assignment ( = ) operator.
php
<?php// Program to create copy of an object// Creating classclass GFG { public $data1; public $data2; public $data3; }// Creating object$obj = new GFG();// Creating clone or copy of object$copy = clone $obj;// Creating object without clone keyword$obj_ref = $obj;// Set values of $obj object$obj->data1 = "Geeks";$obj->data2 = "for";$obj->data3 = "Geeks";// Set values of copied object$copy->data1 = "Python ";$copy->data2 = "for ";$copy->data3 = "Machine learning";// Print values of $obj objectecho "$obj->data1$obj->data2$obj->data3\n";// Print values of $copy objectecho "$copy->data1$copy->data2$copy->data3\n";// Print values of without clone objectecho "$obj_ref->data1$obj_ref->data2$obj_ref->data3\n";?> |
Output:
neveropen Python for Machine learning neveropen
Note: It is clear that cloned object have different values than original object but original and referenced object created by using ‘=’ operator have same value.
References:https://www.php.net/manual/en/language.oop5.cloning.php
