Printing a multi dimensional array using one Foreach loop only

You can use recursive function for this. Only one foreach loop calls recursively.

$cars = array(array("Volvo",22,18),array("BMW",15,13),array("Saab",5,2),array("Land Rover",17,15));

function displayArr($arr) {
    foreach($arr as $key => $value) {
        if(is_array($value)) {
            displayArr($value);
            echo "<br>";
        }
        else {
            echo $value . " . ";
        }
    }
}

displayArr($cars);

Here you go

$cars = array (  array("Volvo",22,18), array("BMW",15,13),array("Saab",5,2), array("Land Rover",17,15) );

foreach($cars as $car) {
    print("Name: ".$car[0]."\n");
    print("Number 1: ".$car[1]."\n");
    print("Number 2: ".$car[2]."\n");
}

Obviously could could make checks to see if the other keys in the inner arrays are set. But seems your array will always contains all the keys.

EDIT:

Based on the comment you left you want to be dynamic as possible so do to that you need to use recursion or the goto control structure.

$cars = array (  array("Volvo",22,18), array("BMW",15,13),array("Saab",5,2), array("Land Rover",17,15) );

foreach($cars as $car) {
    $count = 0;

    A:
    if(isset($car[$count])) {
        print($car[$count] . "\n");
        $count +=1;
        goto A;
    }
}

Here is a method that does not use even one foreach loop

function walk2($item, $key)
{
    echo $key . ' - ' . $item.PHP_EOL;
}

function walk1($car, $key)
{
    array_walk($car, 'walk2');
    echo '------'.PHP_EOL;
}

array_walk($cars, 'walk1');

Gives the output :

0 - Volvo
1 - 22
2 - 18
------
0 - BMW
1 - 15
2 - 13
------
0 - Saab
1 - 5
2 - 2
------
0 - Land Rover
1 - 17
2 - 15
------

Although possibly the question was supposed to make you ask logical questions about the make up of the array so they could test your analytic skill as much as your ability to jump through coding hoops.

Also, even though you are not using a foreach, or any other loop you are making use of the 'C' code that was written for these functions which of course is making use of some sort of loop.

This can give you the result.

<?php
$cars = array (  array("Volvo",22,18), array("BMW",15,13),array("Saab",5,2), array("Land Rover",17,15) );

array_map('fun', $cars);
function fun($cars){
    foreach($cars as $car){
        echo $car."<br />";
    }
}
?>

output

Volvo 22 18 BMW 15 13 Saab 5 2 Land Rover 17 15

use array_map to traverse through the child arrays .

foreach($cars as $key=>$car){
    echo $car[0];
    echo $car[1];
    echo $car[2];
}

$cars = array (
    array("Volvo",22,18), 
    array("BMW",15,13),
    array("Saab",5,2),
    array("Land Rover",17,15) 
);

foreach($cars as $car){
    echo "<pre>";
    print_r($car);
    echo "</pre>";
}