How to add an item to php associative array

Associative arrays (also known as dictionaries) are a very common data type in PHP development. It can store a set of data consisting of keys and values, and the corresponding values ​​can be accessed through the keys. In some cases, we need to dynamically add new key-value pairs to an existing associative array. This article will introduce how to use PHP to implement such an operation.

In PHP, the assignment method of associative arrays is very simple. Just use the bracket operator ([]) directly:

$array = array(
    "key1" => "value1",
    "key2" => "value2"
);

// 通过中括号加键添加元素
$array["key3"] = "value3";

In the above example, first create an array containing two key values Right array, and then added a new key-value pair through $array["key3"]. This method is very simple and straightforward, but is usually used to add a single element.

When we need to add multiple key-value pairs at once, we can use the array_merge() function provided by PHP to merge the original array and the new key-value pairs into a new array:

$array = array(
    "key1" => "value1",
    "key2" => "value2"
);

// 合并数组
$newArray = array_merge($array, array(
    "key3" => "value3",
    "key4" => "value4"
));

In the above example, the array_merge function merges the original array and the new key-value pair into a new array $newArray, while keeping the original array unchanged.

In addition to using the array_merge function, we can also use the " " operator to merge two arrays. This method will not affect the original array:

$array = array(
    "key1" => "value1",
    "key2" => "value2"
);

// 数组合并
$newArray = $array + array(
    "key3" => "value3",
    "key4" => "value4"
);

In the above example, the new array $newArray finally obtained is the same as the new array obtained using the array_merge() function, both containing the original array and new key values. right.

Adding, deleting, modifying and checking associative arrays is one of the most common operations in PHP development. Mastering these operations can greatly improve development efficiency and help us quickly build efficient and stable PHP applications.

The above is the detailed content of How to add an item to php associative array. For more information, please follow other related articles on the PHP Chinese website!