How to copy an array of objects in php

In PHP, copying an object array can be achieved through a variety of methods. This article will introduce three commonly used methods.

1. Use the clone keyword

In PHP, use the clone keyword to copy an object and its properties, but It does not copy the object array. If we want to copy an array of objects, we need to copy each object one by one.

$originalArray = array(new MyClass(), new MyClass(), new MyClass());
$copyArray = array();

foreach ($originalArray as $obj) {
    $copyArray[] = clone $obj;
}

In this example, we first create an array containing three MyClass objects, then use a foreach loop to copy each object one by one and add it into a new array. This method is very effective, but if the array that needs to be copied contains a large number of objects, it will consume a lot of system resources and affect the performance of the program.

2. Using serialization and deserialization

In PHP, use the serialize() function to serialize an object array into a string , and then use the unserialize() function to deserialize the string into a new object array. This method requires relatively few resources and is therefore suitable for copying large arrays of objects.

$originalArray = array(new MyClass(), new MyClass(), new MyClass());
$copyArray = unserialize(serialize($originalArray));

In this example, we first use the serialize() function to serialize the object array into a string, and then use the unserialize() function to Deserialize the string into a new object array.

It should be noted that since the string serialized by the serialize() function includes the state information of the object, we need to ensure that the properties or methods of the object are not serialized as resources. or closure. Otherwise, problems may occur during serialization and deserialization.

3. Use array_map() function

In PHP, use the array_map() function to traverse an array and Performs the same operation on each element and returns a new array. We can use this function to copy an array of objects.

$originalArray = array(new MyClass(), new MyClass(), new MyClass());
$copyArray = array_map(function($obj) { return clone $obj; }, $originalArray);

In this example, we use the array_map() function and anonymous function to copy the object array. This method can achieve copying of object arrays without causing high resource consumption.

Summary

In this article, we introduced three common ways to copy an array of objects: using the clone keyword, using serialization and deserialization, and Use the array_map() function. Each method has its advantages and disadvantages, and we need to choose the appropriate method according to the specific scenario.

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