How to add data type to php array

In PHP, an array is a very commonly used data structure that can store multiple values ​​and access these values ​​based on keys. In PHP, we can store different types of data in arrays, including numbers, strings, objects, and more. In this article, we will detail how to add data types to PHP arrays.

In PHP, there are two ways to add elements to an array, namely using array subscripts and using array functions. For different data types, we can use different methods to add them to the array. Let us introduce them one by one below.

1. Add a string to an array

You can easily add a string to an array using array subscripts. We only need to write code in the following format:

$my_array = array();

// 使用数组下标添加字符串
$my_array[0] = "hello";
$my_array[1] = "world";

In the above code, we create an empty array $my_array, and then use $my_array[0]# The two subscripts ## and $my_array[1] add two strings to the array.

In addition, we can also use the array function

array_push() to add strings to the array. As shown below:

$my_array = array();

// 使用数组函数添加字符串
array_push($my_array, "hello", "world");

In the above code, we first created an empty array

$my_array, and then used the array_push() function to add " hello" and "world" two strings.

Add numbers to the array

Adding numbers to the array is similar to adding strings. We can also use array subscripts and array functions in two ways. The specific code is as follows:

$my_array = array();

// 使用数组下标添加数字
$my_array[0] = 1;
$my_array[1] = 2;

// 使用数组函数添加数字
array_push($my_array, 3, 4);

In the above code, we first create an empty array

$my_array, and then use $my_array[0] and $ my_array[1] Two subscripts add two numbers to the array. Alternatively, we can also use the array_push() function to add numbers to the array.

Add objects to the array

Adding objects to the array requires attention to some details. If we choose to use array subscripting, we must ensure that the object instance has been created. The code is as follows:

class Person {
    public $name;
    public $age;
}

$person1 = new Person();
$person1->name = "张三";
$person1->age = 25;

$person2 = new Person();
$person2->name = "李四";
$person2->age = 30;

$persons = [];
$persons[0] = $person1;
$persons[1] = $person2;

In the above code, we first created the

Person class and created two instances person1 and person2 . We then add the two instances to the array using the two subscripts $persons[0] and $persons[1].

If we use the

array_push() function to add an object, the object must be added to the array as an element.

$persons = [];

array_push($persons, $person1, $person2);

Add Boolean values, arrays and null values ​​to arrays

The way to add Boolean values ​​to arrays is similar to adding numbers and strings, we can use array subscripts and array functions. The code is as follows:

$my_array = array();

// 使用数组下标添加布尔值
$my_array[0] = true;
$my_array[1] = false;

// 使用数组函数添加布尔值
array_push($my_array, true, false);

To add an array to an array, you can use the array subscript method and the function

array_push(). The specific code is as follows:

$my_array = array();

// 使用数组下标添加数组
$my_array[0] = array(1, 2, 3);
$my_array[1] = array("a", "b", "c");

// 使用数组函数添加数组
array_push($my_array, array("x", "y", "z"), array("Hello", "World"));

The same is true for adding null values ​​to an array. You can use array subscripts and the function

array_push(). The code is as follows:

$my_array = array();

// 使用数组下标添加 null 值
$my_array[0] = null;
$my_array[1] = null;

// 使用数组函数添加 null 值
array_push($my_array, null, null);

Summary

Through the introduction of this article, we have learned about the methods of adding different data types to PHP arrays. Data types can be added using both array subscripts and array functions. Which method to use can be chosen according to the actual situation. I hope this article helps you better understand the use of arrays in PHP.

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