PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

Arrays with Different Indices
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This code stores each element in turn in the variable $current and prints it out.
Arrays with Different Indices
In the $products array, you allowed PHP to give each item the default index.This meant
that the first item you added became item 0; the second, item 1; and so on. PHP also supports
arrays in which you can associate any key or index you want with each value.
Initializing an Array
The following code creates an array with product names as keys and prices as values:
$prices = array(‘Tires’=>100, ‘Oil’=>10, ‘Spark Plugs’=>4);
The symbol between the keys and values is simply an equal sign immediately followed
by a greater than symbol.
Accessing the Array Elements
Again, you access the contents using the variable name and a key, so you can access the
information stored in the prices array as $prices[‘Tires’], $prices[‘Oil’], and
$prices[‘Spark Plugs’].
The following code creates the same $prices array. Instead of creating an array with
three elements, this version creates an array with only one element and then adds two
more:
$prices = array( ‘Tires’=>100 );
$prices[‘Oil’] = 10;
$prices[‘Spark Plugs’] = 4;
Here is another slightly different but equivalent piece of code. In this version, you do not
explicitly create an array at all.The array is created for you when you add the first element
to it:
$prices[‘Tires’] = 100;
$prices[‘Oil’] = 10;
$prices[‘Spark Plugs’] = 4;
Using Loops
Because the indices in an array are not numbers, you cannot use a simple counter in a
for loop to work with the array. However, you can use the foreach loop or the list()
and each() constructs.
The foreach loop has a slightly different structure when using associative arrays.You
can use it exactly as you did in the previous example, or you can incorporate the keys as
well:
foreach ($prices as $key => $value) {
echo $key." – ".$value."";
}