How to write a two-dimensional array in php

PHP is a popular programming language used to develop web applications and other types of software. Arrays are a very important data type in PHP and can contain multi-dimensional arrays.

A two-dimensional array is an array containing multiple arrays. Each sub-array is also called a "row" and contains multiple elements. Each element is also called a "column". Here's how to declare and use two-dimensional arrays in PHP.

1. Declaring a two-dimensional array

In PHP, you can declare a two-dimensional array using the array() function. The following is an example of declaring a two-dimensional array:

$people = array(
  array('name' => 'Alice', 'age' => 20),
  array('name' => 'Bob', 'age' => 30),
  array('name' => 'Charlie', 'age' => 40)
);

The above example declares a two-dimensional array named $people, which contains three sub-arrays, each sub-array contains 'name' and ' age' two key-value pairs. You can use the following code to output the contents of the two-dimensional array:

foreach ($people as $person) {
  echo $person['name'] . ' is ' . $person['age'] . ' years old.' . "
";
}

The output result is:

Alice is 20 years old.
Bob is 30 years old.
Charlie is 40 years old.

2. Add elements to the two-dimensional array

You New elements can be added to a two-dimensional array using the subscript syntax. The following code adds a new subarray to the $people array:

$people[] = array('name' => 'David', 'age' => 50);

3. Accessing two-dimensional array elements

You can use the subscript syntax or the foreach loop statement to Access elements in a two-dimensional array. The following code demonstrates how to print the 'name' value of the Charlie subarray in the $people array:

echo $people[2]['name'];

The output result is:

Charlie

4. Modify the two-dimensional array elements

You can use subscript syntax to modify elements in a two-dimensional array. The following sample code modifies Bob's age to 35 years:

$people[1]['age'] = 35;

5. Delete two-dimensional array elements

You can use the unset() function to delete two-dimensional array elements element. The following is the code to delete the Alice subarray in the $people array:

unset($people[0]);

The above is how to create and manipulate two-dimensional arrays in PHP. Two-dimensional arrays are very useful tools when you need to store and manipulate complex data structures. In actual development, you can flexibly use PHP's multi-dimensional arrays according to specific needs to improve the readability and reusability of the code.

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