A multidimensional array contains multiple arrays in it. In other words, it is an array of array(s). In this book, we will be using multidimensional arrays in different examples as they are one of the most popular and efficient ways of storing data for graphs and other tree-type data structures. Let us explore the PHP multidimensional array using an example:

$players = [];
$players[] = ["Name" => "Ronaldo", "Age" => 31, "Country" => "Portugal", "Team" => "Real Madrid"];
$players[] = ["Name" => "Messi", "Age" => 27, "Country" => "Argentina", "Team" => "Barcelona"];
$players[] = ["Name" => "Neymar", "Age" => 24, "Country" => "Brazil", "Team" => "Barcelona"];
$players[] = ["Name" => "Rooney", "Age" => 30, "Country" => "England", "Team" => "Man United"];

foreach($players as $index => $playerInfo) { 
    echo "Info of player # ".($index+1)."
";
    foreach($playerInfo as $key => $value) { 
        echo $key.": ".$value."
";
    } 
    echo "
";
} 

The example we just saw is an example of a two-dimensional array. As a result, we are using two foreach loops to iterate the two-dimensional array. Here is the output of the code:

Info of player # 1 
Name: Ronaldo 
Age: 31 
Country: Portugal 
Team: Real Madrid 

Info of player # 2 
Name: Messi 
Age: 27 
Country: Argentina 
Team: Barcelona 

Info of player # 3 
Name: Neymar 
Age: 24 
Country: Brazil 
Team: Barcelona 

Info of player # 4 
Name: Rooney 
Age: 30 
Country: England 
Team: Man United  

We can create n-dimensional arrays using PHP as per our needs, but we have to remember one thing: the more dimensions we add, the more complex the structure becomes. We as humans usually visualize three dimensions, so in order to have more than three-dimensional arrays, we must have a solid understanding of how an array works in multiple dimensions.