How to write list array in php

PHP is a popular server-side programming language that provides various data types and data structures, including list arrays. In this article, we will discuss how to write list array in PHP.

First of all, we need to understand what a list array is. In PHP, a list array is an ordered collection in which different types of data (such as integers, strings, booleans, etc.) can be stored and they can be referenced in a single variable.

In PHP, we can use the following syntax to create a list array:

$list = array(item1, item2, item3, ...);

Among them, $list is the name of the list array we created, item1, item2, item3, etc. are the names we want to create. The value of the item stored in the array. We can also use the following syntax to create an associated list array:

$list = array('key1' => value1, 'key2' => value2, 'key3' => value3, ...);

In this case, each item in the array has an associated key (such as 'key1', 'key2', etc.) , so that we can reference their values ​​by key.

With the following example program, we can create a simple list array:

$list = array('apple', 'banana', 'orange', 'pear');

In this example, we create a list array containing four string values.

We can use the following syntax to access items in the list array:

$value = $list[index];

Among them, $value is the value of the item we want to reference, $list is the list array we want to access, index is the index value of the item we want to access. Please note that unlike many other programming languages, the indexing of list arrays in PHP starts from 0.

Another way to access items in a list array is to use a foreach loop. The following example program demonstrates how to use a foreach loop to access a list array:

foreach($list as $item) {
    echo $item . "<br/>";
}

In this example, we use a foreach loop to traverse the entire list array and store the value of the item in the $item variable on each iteration middle. We then use the echo statement to output the value of the item to the web browser.

We can also use the following syntax to delete items from the list array:

unset($list[index]);

Where, $list is the list array of the item we want to delete, and index is the index value of the item we want to delete. Note that after deleting an item, you will be left with an empty item in the list array with the same index as the item we deleted.

In addition to deleting items, we can also use the following syntax to add items to the list array:

$list[] = value;

Among them, $list is the list array we want to add items to, and value is the value we want to add. new value. When we add a new item to the list array using this method, PHP will automatically assign a new index value to the item.

In PHP, the list array is a very useful data structure that allows us to store and reference different types of data in an ordered manner. By using the above syntax and sample program, we can easily create, access, modify and delete items in the list array.

The above is the detailed content of How to write list array in php. For more information, please follow other related articles on the PHP Chinese website!