How to handle the value of object array in php

PHP is a very popular programming language. Although it was originally designed to generate dynamic web pages on the server side, it has now become a general-purpose programming language. There is a very important and commonly used data type in the PHP language - object array, which is often used to store large amounts of data. In PHP, the values ​​of object arrays can be obtained and manipulated through some simple techniques. This article will introduce how PHP handles the values ​​of object arrays.

1. Understand the basic structure of object array

In PHP, object array refers to a collection of multiple objects in an array. Each object is composed of properties and methods. data structure. When using object arrays, we usually define a class, instantiate multiple objects of that class, and then put these objects into an array. For example, the following code:

class Student{
    public $name;
    public $age;
    public $score;
}
$stu1=new Student();
$stu1->name="张三";
$stu1->age=20;
$stu1->score=88;
$stu2=new Student();
$stu2->name="李四";
$stu2->age=21;
$stu2->score=90;
$stu_arr=array($stu1,$stu2);

This code defines a Student class, instantiates two student objects $stu1 and $stu2, and puts these two objects into an object array $stu_arr . Each student object contains three attributes: name, age, and grade. This constitutes a simple array of objects.

2. Get the value of the object array

Getting the value in the object array is an essential skill for us to operate the object array. There are two ways to get the value in the object array: through index value and loop traversal.

1. Obtaining the value of the object array through the index value

Getting the value of the object array through the index value is very simple, we only need to use the array subscript. For the above code, to get some values ​​​​in the array, we can write like this:

echo $stu_arr[0]->name;  //输出“张三”
echo $stu_arr[1]->score; //输出“90”

Here $stu_arr[0] represents the first object in the array, $stu_arr[1] represents the first object in the array For the second object, -> is followed by the attribute name to be obtained. Using this method, we can easily get any value in the object array.

2. Obtain through loop traversal

If we need to obtain all the values ​​​​in the entire object array, then using loop traversal is a better choice. In PHP, we can use a foreach loop to iterate through an array of objects and get each value inside. For the above code, we can traverse the object array in the following way:

foreach($stu_arr as $stu){
    echo $stu->name."的年龄是".$stu->age."，成绩是".$stu->score."
";
}

The $stu here represents an object in the array in each loop, and we can perform any operation on it. In this way, we can easily output the contents of the entire object array.

3. Modify the value of the object array

In actual development, we often need to modify a certain value in the object array. To modify the values ​​in the object array, we only need to use -> to access the object properties and assign a new value to it, just like when reading. For example, if we want to change the name of the first student in $stu_arr from "Zhang San" to "Wang Wu", we can write it like this:

$stu_arr[0]->name="王五";

In this way, we have successfully modified the object A value in the array.

4. Deleting the value of the object array

Deleting a value in the object array is also very simple. We only need to specify the objects to be deleted in the array through the unset() function. For example, if we want to delete the second student in the array, we can write:

unset($stu_arr[1]);

This statement deletes the second object in the array. Of course, we can also use loop traversal to delete all objects in the entire array.

5. Summary

The above is all about how PHP converts the value of an object array. After mastering these basic knowledge, we can easily use object arrays to store and operate data. Of course, in actual development, there are many more advanced and complex usages waiting for us to explore and use.

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