Outline
o
What is an array ?
o
Indexed array
o
Associative array
o
Multidimensional array
What is an Array?

An array is a special variable, which can store
multiple values in one single variable.

An array can hold many values under a single name,
and you can access the values by referring to an
index number.
What is an array?

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 best solution here is to use an array!

An array can hold all your variable values under a single name. And you
can access the values by referring to the array name.

Each element in the array has its own index so that it can be easily accessed.
What is an array?

In PHP, the array() function is used to create an array:
array();
Kind of arrays in PHP

Indexed 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
Indexed Arrays

A numeric array stores each array element with a
numeric index.

There are two ways to create indexed arrays:
Indexed Arrays
In the following example the index are automatically assigned (the index
1.
starts at 0): $array_name = array(val1, val2, val3,val4,……);
- $cars = array ("Saab","Volvo","BMW","Toyota");
The following example we assign the index manually:]
1.
1.
$cars[0]="Saab";
2.
$cars[1]="Volvo";
3.
$cars[2]="BMW";
4.
$cars[3]="Toyota";
Indexed Arrays - Example
<?php
$cars[0]="Saab";
$cars[1]="Volvo";
$cars[2]="BMW";
$cars[3]="Toyota";
echo $cars[0] . " and " . $cars[1] . " are Swedish
cars.";
Indexed Arrays - Example
<?php
$array = array(1, 2,3,4,5,6,7,8,9);
for ($i = 0; $i < 9; $i++)
{
echo “Number : “. $array[$i];
}
?>
Print_r() Function

Print construction of array as group of locations and
the value stored in it
print_r ($expression [, bool $return = false ] )
Print_r()
<?php
$arr = array(1,2,3,4,5);
Print_r($arr);
?>
Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 )
Count() Function

This is build in function ,counts all elements in an
array, or something in an object.
int count ($var [, int $mode = COUNT_NORMAL ] )
Count Function - Example
<?php
$a[0] = 1;
$a[1] = 3;
$a[2] = 5;
$result = count($a); // $result == 3
$b[0] = 7;
$b[5] = 9;
$b[10] = 11;
$result = count($b); // $result == 3
$result = count(null);// $result == 0
$result = count(false);// $result == 1
?>
Count Function - Example
<?php
$array = array(“M”, ”u”,”n”,”e”,”e”,”r”);
for ($i = 0; $i < count($array); $i++)
{
echo $array[$i];
}
?>
Foreach
foreach ($array as $value)
{
code to be executed;
}

For every loop iteration, the value of the current array element is assigned
to $value (and the array pointer is moved by one) - so on the next loop
iteration, you'll be looking at the next array value.
Foreach - Example
<?php
$x=array("one","two","three");
foreach ($x as $value)
{
echo $value . "<br />";
}
?>
Foreach - Example
<?php
$colors = array('red', 'blue', 'green', 'yellow');
foreach ($colors as $color) {
echo "Do you like $color?\n";
}
?>
in_array() Function
in_array(search,array,type)

The in_array() function searches an array for a specific value.

This function returns TRUE if the value is found in the array, or FALSE otherwise.
Parameter
Description
search
Required. Specifies the what to search for
array
Required. Specifies the array to search
type
Optional. If this parameter is set, the in_array() function searches for the search-string and
specific type in the array
Note: If the search parameter is a string and the type parameter is set to TRUE,
the search is case-sensitive.
in_array() Function - Example
<?php
$os = array("Mac", “W7", “W8", "Linux");
if (in_array(“XP", $os)) {
echo "Got XP";
}
if (in_array(“Mac", $os)) {
echo "Got Mac";
}
?>
Associative Arrays

An associative array, each ID key is associated with a value.

When storing data about specific named values, a numerical
array is not always the best way to do it.

With associative arrays we can use the values as keys and
assign values to them.
Associative Arrays
$array_name= array($index1=>$val1, $index1=>$val1,…..);
•
$ages = array("Peter"=>32, "Quagmire"=>30, "Joe"=>34);
or
•
$ages['Peter'] = "32";
$ages['Quagmire'] = "30";
$ages['Joe'] = "34";
Associative Arrays
<?php
$arr = array("foo" => "bar", 12 => true);
echo $arr["foo"]; // bar
echo $arr[12];
?>
// 1
Associative Arrays - example
<?php
// This array is the same as ...
array(5 => 43, 32, 56, "b" => 12);
// ...this array
array(5 => 43, 6 => 32, 7 => 56, "b" => 12);
?>
Associative Arrays - example
<?php
$ages['Peter'] = "32";
$ages['Quagmire'] = "30";
$ages['Joe'] = "34";
echo "Peter is " . $ages['Peter'] . " years old.";
?>
Associative Arrays - example
<?php
$arr = array(5 => 1, 12 => 2);
$arr[] = 56;
// This is the same as $arr[13] = 56;
// at this point of the script
$arr["x"] = 42; // This adds a new element to
// the array with key "x"
unset($arr[5]); // This removes the element from the array
unset($arr);
?>
// This deletes the whole array
Associative Arrays - example
<?php
$arr = array("somearray" => array(6 => 5, 13 => 9, "a" => 42));
echo $arr["somearray"][6];
// 5
echo $arr["somearray"][13]; // 9
echo $arr["somearray"]["a"]; // 42
?>
Multidimensional Arrays

In a multidimensional array, each element in the main array can also be an
array. And each element in the sub-array can be an array,
$myArray = array( array( value1, value2, value3 ), array( value4, value5, value6 ), array( value7,
value8, value9 ) );
Multidimensional Arrays
<?php
$fruits = array ( "fruits"
=> array ( "a" => "orange",
"b" => "banana“,"c" => "apple”),"numbers" => array ( 1,
2,3,4,5,6), "holes"
=> array ("first“,5 => "second“,"third
”));
echo $fruits["holes"][5];
// prints "second"
echo $fruits["fruits"]["a"]; // prints "orange"
?>
Multidimensional Arrays
<?php
$families = array(“capital"=>array(“A“,“B“,“C”),
“small"=>array(“a”, “b”, “c”),
“number"=>array(“1“,“2“,”3”));
foreach($families as $value)
{foreach($value as $values)
{echo $values.” ”;}
Echo “<br/>”}
?>
Multidimensional Arrays
<?php
$try[] = array("11", "12", "15", "22", "41", "42");
$try[] = array("6", "7", "16", "17", "22", "23");
$count = count ($try);
for ($i=0; $i<$count; $i++)
{
$countmore=count($try[0]);
for ($j=0; $j < $countmore; $j++)
{
print ("i$i j$j " . $try[$i][$j] . "<br> ");
}
print ("<br>");
}
?>
Multidimensional Arrays
<?php
$try[] = array("11", "12", "15", "22", "41", "42");
$try[] = array("6", "7", "16", "17", "22", "23"); $count = count ($try); for ($i=0; $i<$count; $i++)
{
$countmore=count($try[0]);
for ($j=0; $j < $countmore; $j++)
{ print ("i$i j$j " . $try[$i][$j] . "<br> "); }
print ("<br>");
}
?>