How to push associative array in php

In PHP, there are two main array types: indexed arrays and associative arrays. Indexed arrays use numbers as keys, while associative arrays use strings as keys. When you need to add a new element to the end of an associative array, you can use the array_push() function. However, since the keys of an associative array are not consecutive numbers, the array_push() function cannot be used directly. This article will introduce how to push associative arrays in PHP.

Definition of associative array

In PHP, you can define an associative array in the following way:

$person = array(
    'name' => 'John',
    'age' => 30,
    'gender' => 'male'
);

The $person variable above is an associative array, which contains three Key-value pairs. The key names are 'name', 'age' and 'gender', and the corresponding values ​​are 'John', 30 and 'male'.

Add elements to an associative array

If you want to add an element to an associative array, you can use the following code:

$person['occupation'] = 'programmer';

This will add a new element to the associative array $person The key-value pair, the key is 'occupation' and the value is 'programmer'. By adding elements in this way, you can add elements to an associative array.

Add an element to the end of an associative array

When adding an element to the end of an associative array, you can use the following code:

$person['phone_number'] = '123456789';

This will add to the associative array $person A new key-value pair with the key name 'phone_number' and the value '123456789'. However, when you need to add elements multiple times, it is more convenient to use the array_push() function.

Using the array_push() function in an associative array

The array_push() function is used to add one or more elements to the end of the array, but it can only be used to index the array and cannot be used for associative arrays. So, in order to add an element to an associative array, you can use the following code:

array_push($person, array('phone_number' => '123456789'));

The above code will add a new element to the $person array with a value containing the 'phone_number' key and '123456789' Associative array of values. This adds elements to an associative array, but this method may become inconvenient when adding elements multiple times.

To make the code more concise, you can define the new element as an associative array and then add it to the original array with the following code:

$person = array_merge($person, array('phone_number' => '123456789'));

The above code will create a new association An array where one of the keys is 'phone_number' and the value is '123456789', which is then merged into the original array $person using the array_merge() function.

Summary

In PHP, you can add elements to an associative array using the above method. Although it is not very convenient to use the array_push() function, it can play a certain role when you need to add multiple elements. Use the array_merge() function to merge an associative array into another array and make the code more concise. Proficient in these methods, you can better operate associative arrays and improve development efficiency.

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