In the previous pages, we have described arrays that are a single list of key/value pairs.
However, sometimes you want to store values with more than one key. For this, we have multidimensional arrays.
PHP - Multidimensional Arrays
A multidimensional array is an array containing one or more arrays.
PHP supports multidimensional arrays that are two, three, four, five, or more levels deep. However, arrays more than three levels deep are hard to manage for most people.
The dimension of an array indicates the number of indices you need to select an element.
- For a two-dimensional array you need two indices to select an element
- For a three-dimensional array you need three indices to select an element
PHP - Two-dimensional Arrays
A two-dimensional array is an array of arrays [a three-dimensional array is an array of arrays of arrays].
First, take a look at the following table:
| Volvo | 22 | 18 |
| BMW | 15 | 13 |
| Saab | 5 | 2 |
| Land Rover | 17 | 15 |
We can store the data from the table above in a two-dimensional array, like this:
$cars = array [
array["Volvo",22,18],
array["BMW",15,13],
array["Saab",5,2],
array["Land Rover",17,15]
];
Now the two-dimensional $cars array contains four arrays, and it has two indices: row and column.
To get access to the elements of the $cars array we must point to the two indices [row and column]:
Example
Try it Yourself »
We
can also put a for loop inside another for loop to get the elements of the $cars array [we still have to point to the two indices]:
Example
Try it Yourself »
Complete PHP Array Reference
For a complete reference of all array functions, go to our complete PHP Array Reference.
The reference contains a brief description, and examples of use, for each function!
Multi-dimensional arrays are such type of arrays which stores an another array at each index instead of single element. In other words, define multi-dimensional arrays as array of arrays. As the name suggests, every element in this array can be an array and they can also hold other sub-arrays within. Arrays or sub-arrays in multidimensional arrays can be accessed using multiple dimensions.
Dimensions: Dimensions of multidimensional array indicates the number of indices needed to select an element. For a two dimensional array two indices to select an element.
Two dimensional array: It is the simplest form of a multidimensional array. It can be created using nested array. These type of arrays can be used to store any type of elements, but the index is always a number. By default, the index starts with zero.
Syntax:
array [
array [elements...],
array [elements...],
...
]Example:
Output:
Array
[
[0] => Array
[
[0] => Ankit
[1] => Ram
[2] => Shyam
]
[1] => Array
[
[0] => Unnao
[1] => Trichy
[2] => Kanpur
]
]
Two dimensional associative array: Al associative array is similar to indexed array but instead of linear storage [indexed storage], every value can be assigned with a user-defined key of string type.
Example:
Output:
Display Marks:
Array
[
[Ankit] => Array
[
[C] => 95
[DCO] => 85
[FOL] => 74
]
[Ram] => Array
[
[C] => 78
[DCO] => 98
[FOL] => 46
]
[Anoop] => Array
[
[C] => 88
[DCO] => 46
[FOL] => 99
]
]
Three Dimensional Array: It is the form of multidimensional array. Initialization in Three-Dimensional array is same as that of Two-dimensional arrays. The difference is as the number of dimension increases so the number of nested braces will also increase.
Syntax:
array [
array [
array [elements...],
array [elements...],
...
],
array [
array [elements...],
array [elements...],
...
],
...
]Example:
Output:
Array
[
[0] => Array
[
[0] => Array
[
[0] => 1
[1] => 2
]
[1] => Array
[
[0] => 3
[1] => 4
]
]
[1] => Array
[
[0] => Array
[
[0] => 5
[1] => 6
]
[1] => Array
[
[0] => 7
[1] => 8
]
]
]
Accessing multidimensional array elements: There are mainly two ways to access multidimensional array elements in PHP.
- Elements can be accessed using dimensions as array_name[‘first dimension’][‘second dimension’].
- Elements can be accessed using for loop.
- Elements can be accessed using for each loop.
Example:
Output:
95 95 85 74 78 98 46 88 46 99
PHP is a server-side scripting language designed specifically for web development. You can learn PHP from the ground up by following this PHP Tutorial and PHP Examples.