PHP
5 Arrays
An array
stores multiple values in one single variable:
Example
<?php
$cars
= array("Volvo", "BMW", "Toyota");
echo
"I like " . $cars[0] . ", " . $cars[1] . " and "
. $cars[2] . ".";
?>
What is an
Array?
An array is
a special variable, which can hold more than one value at a time.
If you have
a list of items (a list of car names, for example), storing the cars in single
variables could look like this:
$cars1
= "Volvo";
$cars2
= "BMW";
$cars3
= "Toyota";
However,
what if you want to loop through the cars and find a specific one? And what if
you had not 3 cars, but 300?
The solution
is to create an array!
An array can
hold many values under a single name, and you can access the values by
referring to an index number.
Create an
Array in PHP
In PHP, the
array() function is used to create an array:
array();
In PHP,
there are three types of arrays:
Indexed
arrays - Arrays with a numeric index
Associative
arrays - Arrays with named keys
Multidimensional
arrays - Arrays containing one or more arrays
PHP Indexed
Arrays
There are
two ways to create indexed arrays:
The index
can be assigned automatically (index always starts at 0), like this:
$cars
= array("Volvo", "BMW", "Toyota");
or
the index can be assigned manually:
$cars[0]
= "Volvo";
$cars[1]
= "BMW";
$cars[2]
= "Toyota";
The
following example creates an indexed array named $cars, assigns three elements
to it, and then prints a text containing the array values:
Example
<?php
$cars
= array("Volvo", "BMW", "Toyota");
echo
"I like " . $cars[0] . ", " . $cars[1] . " and "
. $cars[2] . ".";
?>
Get The
Length of an Array - The count() Function
The count()
function is used to return the length (the number of elements) of an array:
Example
<?php
$cars
= array("Volvo", "BMW", "Toyota");
echo
count($cars);
?>
Loop Through
an Indexed Array
To loop
through and print all the values of an indexed array, you could use a for loop,
like this:
Example
<?php
$cars
= array("Volvo", "BMW", "Toyota");
$arrlength
= count($cars);
for($x
= 0; $x < $arrlength; $x++) {
echo $cars[$x];
echo "<br>";
}
?>
PHP
Associative Arrays
Associative
arrays are arrays that use named keys that you assign to them.
There are
two ways to create an associative array:
$age
= array("Peter"=>"35",
"Ben"=>"37", "Joe"=>"43");
or:
$age['Peter']
= "35";
$age['Ben']
= "37";
$age['Joe']
= "43";
The named
keys can then be used in a script:
Example
<?php
$age
= array("Peter"=>"35",
"Ben"=>"37", "Joe"=>"43");
echo
"Peter is " . $age['Peter'] . " years old.";
?>
Loop Through
an Associative Array
To loop
through and print all the values of an associative array, you could use a
foreach loop, like this:
Example
<?php
$age
= array("Peter"=>"35",
"Ben"=>"37", "Joe"=>"43");
foreach($age
as $x => $x_value) {
echo "Key=" . $x . ", Value="
. $x_value;
echo "<br>";
}
?>
Multidimensional
Arrays
Multidimensional
arrays will be explained in the PHP advanced section.
Complete PHP
Array Reference
For a
complete reference of all array functions, go to our complete PHP Array
Reference.
The
reference contains a brief description, and examples of use, for each function!
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