How to get an array in php

PHP is a very popular server-side scripting language with a powerful array system. Array is one of the most important data types in PHP. It can save multiple values ​​and is very useful when processing some data, such as form data or database query results. In this article, we will explore how to create and use arrays in PHP.

1. PHP Array Basics

In PHP, arrays can contain any type of value, such as numbers, strings, and objects. The values ​​of array elements can be scalars, other arrays, or even functions.

The simplest way to define an array is to use the array() function, which accepts any number of parameters, each parameter being the value of an element in the array.

For example, the following code defines a simple array:

$fruits = array('apple', 'banana', 'orange');

We can also add values ​​to the array:

$fruits[] = 'grape';

In this case, we add $ A new element "grape" is added to the fruits array. We can also create arrays in the form of key-value pairs:

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

Here, we use "name" and "age" as keys and map them to the corresponding values. We can access the value through the key of the array element:

echo $person['name']; // 输出 John

2. Array traversal

In PHP, we can use loop statements to traverse the elements in the array. The most commonly used is the foreach loop, which can output each element in the array in order:

foreach ($fruits as $fruit) {
    echo $fruit . '<br>';
}

This loop traverses each element in the $fruits array and assigns it to the $fruit variable for output.

We can also use a foreach loop to output key-value pairs:

foreach ($person as $key => $value) {
    echo "$key: $value <br>";
}

This loop traverses each key-value pair in the $person array and assigns it to $key and $ respectively. value variable.

3. Union array

PHP also supports the union of multiple arrays. In this process, the elements in multiple arrays are merged into a new array. The following example creates a union array:

$fruits = array('apple', 'banana', 'orange');
$vegetables = array('carrot', 'tomato', 'spinach');
$food = array_merge($fruits, $vegetables);

Here, we use the array_merge() function to merge the $fruits and $vegetables arrays into a new array $food. We can use a foreach loop to traverse the elements in the new array:

foreach ($food as $item) {
    echo $item . '<br>';
}

4. Multidimensional arrays

In PHP, we can use multidimensional arrays to store more complex data structures. A multidimensional array is an array with other arrays nested within it.

The following is a simple multi-dimensional array example:

$products = array(
    array('name' => 'Apple', 'price' => 1.00),
    array('name' => 'Banana', 'price' => 0.50),
    array('name' => 'Orange', 'price' => 1.20)
);

In this example, the $products array contains three arrays, each array represents a separate product, which contains the product name and price attributes.

We can use a foreach loop to traverse all elements in the multidimensional array:

foreach ($products as $product) {
    echo $product['name'] . ': $' . $product['price'] . '<br>';
}

This loop first traverses each element in the $products array, and then traverses all keys in the current element inside the loop -value pair.

5. Summary

PHP provides a very powerful array system that can help developers easily handle various types of data. In this article, we explore how to create and use arrays in PHP, and introduce relevant knowledge points about array traversal, associative arrays and multi-dimensional arrays. We hope it will be helpful to readers.

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