How to convert associative array into indexed array in php

As we all know, PHP is a popular scripting language for web development. Among them, array, as a basic data type, is widely used in various scenarios. In daily development, sometimes we need to convert an associative array into an index array. This article will introduce how to use PHP functions to achieve this function.

1. Array types in PHP

In PHP, arrays are divided into two types: index arrays and associative arrays. The index array's subscript starts from 0, while the associative array has a custom subscript.

The following are examples of two types of arrays:

$index_array = array('apple', 'banana', 'orange');
$assoc_array = array('a' => 'apple', 'b' => 'banana', 'o' => 'orange');

2. Convert associative array to index array

When we need to convert an associative array into an index array, we need to use PHP built-in function array_values(). The specific implementation is as follows:

$assoc_array = array('a' => 'apple', 'b' => 'banana', 'o' => 'orange');
$index_array = array_values($assoc_array);
print_r($index_array);

Output:

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
)

By using the array_values() function, we successfully converted the associative array $assoc_array into the index array $index_array. Where, the function returns an indexed array containing only the array values.

It should be noted that using the array_values() function will reset the index identifier of the array and convert it into an index array.

3. Performance considerations

In actual development, we need to take performance factors into consideration. If there is a large amount of data that needs to be converted into indexed arrays, and the size and keys of these arrays are set relatively randomly, then the function array_values() may have some impact on the performance of the server. The reason is that the function needs to operate on each key and save the results into a separate array.

In this case, we can use a foreach loop to achieve the same result. The code is as follows:

$assoc_array = array('a' => 'apple', 'b' => 'banana', 'o' => 'orange');
$index_array = array();
foreach($assoc_array as $value) {
    $index_array[] = $value;
}
print_r($index_array);

Output:

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
)

Using the foreach loop, we can convert the associative array into an index array more efficiently.

4. Summary

PHP is a popular scripting language for Web development, in which arrays are widely used as its basic data type. This article briefly introduces the two array types in PHP: indexed arrays and associative arrays. When we need to convert an associative array into an indexed array, we can use the built-in array_values() function. However, when performance is a concern, it may be more efficient to use a foreach loop.

I hope this article can help you master the array operations in the PHP language and how to optimize the code in actual development.

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