Home Backend Development PHP Problem Let's talk about the three different array types in PHP

Let's talk about the three different array types in PHP

Apr 10, 2023 am 09:41 AM

In PHP, arrays are one of the most commonly used data structures. An array is a data structure containing one or more elements, each with a unique key (index). In PHP, there are three different array types: numerically indexed arrays, associative arrays, and multidimensional arrays.

The first type is a numerical index array. The index of this array is a number, starting from 0 and increasing. Numerically indexed arrays can be created using the array() function or the abbreviated [] notation. For example:

//使用数组()函数创建数字索引数组
$numbers = array(1, 2, 3, 4, 5);

//使用简写的[]符号创建数字索引数组
$numbers = [1, 2, 3, 4, 5];
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When you need to access an array element, you can use the index of the array, for example $numbers[2] will return 3.

The second type is an associative array. The index of this array is a string, also called a key-value array. Associative arrays can be created using the array() function or the abbreviated [] notation. For example:

//使用数组()函数创建关联数组
$colors = array(
  "red" => "#FF0000",
  "green" => "#00FF00",
  "blue" => "#0000FF"
);

//使用简写的[]符号创建关联数组
$colors = [
  "red" => "#FF0000",
  "green" => "#00FF00",
  "blue" => "#0000FF"
];
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When you need to access an array element, you can use the corresponding key.

The third type is a multidimensional array, which contains other arrays and can also be called an array of arrays. Multidimensional arrays can be of any dimension. For example, the following is a two-dimensional array:

$users = [
  [
    "name" => "John",
    "age" => 30,
    "email" => "john@example.com"
  ],
  [
    "name" => "Jane",
    "age" => 25,
    "email" => "jane@example.com"
  ],
  [
    "name" => "Bob",
    "age" => 40,
    "email" => "bob@example.com"
  ]
];
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To access elements in a multidimensional array, two indices are used. For example, $users0 will return John.

In addition to the above array types, PHP also provides some useful array functions, such as array_push(), array_pop(), array_shift(), array_unshift(), array_slice(), etc. These functions help developers process data more efficiently when manipulating arrays.

In PHP, array is a powerful and commonly used data structure. With the help of arrays and their related functions, developers can easily manipulate and process a variety of data.

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