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Open Source Technologies

Notes Here’s an example for the use of static that runs initialization code the first time (and only the
first time) the function is run:
Example: function do _something()
{
static first _time = true;

if (first _time) {
// Execute this code only the first time the
function is

→called
...
}
// Execute the function’s main logic every time
the function is
→called
...

}
7.8 Arrays

A variable is a storage area holding a number or text. The problem is, a variable will hold only
one value. An array is a special variable, which can store multiple values in one single variable.
An array in PHP is actually an ordered map. A map is a type that associates values to keys. This
type is optimized for several different uses; it can be treated as an array, list (vector), hash table
(an implementation of a map), dictionary, collection, stack, queue, and probably more. As array
values can be other arrays, trees and multidimensional arrays are also possible.

For now, let’s take a look at the general syntax of the array() statement:

Array array([key]=>[value], [index2]=>[value], ...);
In PHP, there are three kinds of arrays:

• Numeric array - An array with a numeric index.
• Associative array - An array where each ID key is associated with a value.
• Multidimensional array - An array containing one or more arrays.

Numeric Arrays
A numeric array stores each array element with a numeric index. There are two methods to
create a numeric array.

1. In the following example the index are automatically assigned (the index starts at 0):
$cars=array(“Saab”,”Volvo”,”BMW”,”Toyota”);
2. In the following example we assign the index manually:

$cars[0]=”Saab”;

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