How to add elements to php multivariate array

PHP is a widely used server-side scripting language. Its excellent array functions allow developers to easily manage and organize data. In PHP, multivariate arrays are array types often used by developers, also known as nested arrays. A multivariate array can store not only simple single values ​​but also other arrays, making it a powerful tool for organizing complex data structures. In this article, we will discuss how to add elements to a multivariate array using PHP’s built-in functions.

Multiple arrays

First of all, we need to understand what a multivariate array is. A multivariate array refers to an array that contains an array, that is, the elements in the array are also an array. A multivariate array can have two or more key and value pairs, and each key and value pair can be an array. The following is an example of a simple multivariate array:

$employees = [
    [
        'name' => 'John',
        'age' => 30,
        'position' => 'Developer'
    ],
    [
        'name' => 'Jane',
        'age' => 25,
        'position' => 'Designer'
    ],
    [
        'name' => 'Bob',
        'age' => 40,
        'position' => 'Manager'
    ]
];

In the above code, we define a multivariate array named $employees and contains three elements, each element It also contains three key and value pairs of 'name', 'age' and 'position'. We can access elements in a multivariate array in the following ways:

echo $employees[0]['name']; // 输出 'John'
echo $employees[1]['position']; // 输出 'Designer'

Use the built-in function array_push() to add elements

When we need to add elements to a multivariate array, we can use PHP's built-in Functionarray_push(). This function adds one or more elements to the end of the array. For multivariate arrays, we can add an element as another array.

For example, we can add Mike to the $employees array in the above example:

$new_employee = [
    'name' => 'Mike',
    'age' => 35,
    'position' => 'Sales'
];
array_push($employees, $new_employee);

With the above code, we create a new array $new_employee and append it to $employees The end of the array. We can confirm whether the new element has been added to the array in the following way:

print_r($employees);

The output is as follows:

Array
(
    [0] => Array
        (
            [name] => John
            [age] => 30
            [position] => Developer
        )

    [1] => Array
        (
            [name] => Jane
            [age] => 25
            [position] => Designer
        )

    [2] => Array
        (
            [name] => Bob
            [age] => 40
            [position] => Manager
        )

    [3] => Array
        (
            [name] => Mike
            [age] => 35
            [position] => Sales
        )

)

We can see that the new element has been successfully added to the $employees array .

Use the built-in function [] to add elements

In addition to using the array_push() function, we can also use the new syntactic sugar added after PHP 5.4 version: use [] to Elements are added directly to the end of the array. The following is an example of adding an element to a multivariate array:

$employees[] = [
    'name' => 'Tom',
    'age' => 32,
    'position' => 'Engineer'
];

If we want to add an element in the middle of a multivariate array, we can do it by specifying the key name:

$employees[2] = [
    'name' => 'David',
    'age' => 28,
    'position' => 'Programmer'
];

In In the above code, we add a new element to the $employees array at the third position and set its key to 2.

Conclusion

Multiple arrays are a powerful tool in PHP for organizing complex data. In this article, we discussed how to add elements to a multivariate array using PHP’s built-in functions. We learned to use the array_push() function to add one or more elements to the end of the array, and to use the syntactic sugar added after PHP 5.4 to add elements directly to the end of the array. Regardless of the approach, we can easily manipulate the elements in a multivariate array to better process and organize the data.

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