PHP Tutorials - Arrays (Part 2)

PHP Tutorials - Arrays (Part 2)

In this PHP Tutorial you will learn Arrays (Part 2) - Looping with foreach( ), Sorting arrays and Using Multidimensional Arrays.

Looping with foreach( ):

The easiest way to iterate through each element of an array is with foreach( ).
The foreach( ) construct lets you run a code block once for each element in an array.

Example:

$fruits = array(‘apple’, ‘banana’, ‘orange’);
print “<table>\n”;
foreach ($fruits as $fruit) {
print “<tr><td>$fruit</td></tr>\n”;
}
print ‘</table>’;

This will print:

<table>
<tr><td>apple</td></tr>
<tr><td>banana</td></tr>
<tr><td>orange</td></tr>
</table>

if you want to know what element you're on as you're iterating through a numeric array, use for( ) instead of foreach( ).

Your for( ) loop should depend on a loop variable that starts at 0 and continues up to one less than the number of elements in the array.

Example:

$fruits = array(‘apple’, ‘banana’, ‘orange’);
$num = count($fruits);
for ($i = 0, $i < $num; $i++) {
print "Fruit number $i is $fruits[$i]\n";
}

This will print:

Fruit number 0 is apple
Fruit number 0 is banana
Fruit number 0 is orange

Sorting arrays:

To sort array values, you can use the function sort().

Example:

$dinner = array('Sweet Corn and Asparagus',
'Lemon Chicken',
'Braised Bamboo Fungus');
$meal = array('breakfast' => 'Walnut Bun',
'lunch' => 'Cashew Nuts and White Mushrooms',
'snack' => 'Dried Mulberries',
'dinner' => 'Eggplant with Chili Sauce');
sort($dinner);
sort($meal);
foreach ($dinner as $key => $value) {
print "\$dinner: $key $value\n";
}
foreach ($meal as $key => $value) {
print " \$meal: $key $value\n";
}

This will print:

$dinner: 0 Braised Bamboo Fungus
$dinner: 1 Lemon Chicken
$dinner: 2 Sweet Corn and Asparagus
$meal: 0 Cashew Nuts and White Mushrooms
$meal: 1 Dried Mulberries
$meal: 2 Eggplant with Chili Sauce
$meal: 3 Walnut Bun

can also sort arrays by key with ksort( ). This keeps key/value pairs together, but orders them by key.

Example:

$meal = array('breakfast' => 'Walnut Bun',
'lunch' => 'Cashew Nuts and White Mushrooms',
'snack' => 'Dried Mulberries',
'dinner' => 'Eggplant with Chili Sauce');
ksort($meal);
foreach ($meal as $key => $value) {
print "\$meal: $key $value\n";
}

This will print:

$meal: breakfast Walnut Bun
$meal: dinner Eggplant with Chili Sauce
$meal: lunch Cashew Nuts and White Mushrooms
$meal: snack Dried Mulberries

Using Multidimensional Arrays:

Use the array( ) construct to create arrays that have more arrays as element values.

Example:

$lunches = array( array('Chicken','Eggplant','Rice'),
array('Beef','Scallions','Noodles'),
array('Eggplant','Tofu'));
print $lunches[0][0];
print $lunches[2][1];

This will print:

Chicken
Tofu