An array can store multiple values in a single variable. Arrays can be numeric, associative, or multidimensional. Numeric arrays use numeric indexes to store elements, while associative arrays use named keys. Multidimensional arrays contain arrays as elements. PHP has functions to sort and manipulate array elements, such as sort(), rsort(), asort(), arsort(), ksort(), and krsort().

1. PHP Arrays

2. What is an Array?
-An array can store one or more
values in a single variable name.
-Each element in the array is
assigned its own ID so that it can
be easily accessed.
-$array[key] = value;

3. 3 Kinds of Arrays
1) Numeric Array
2) Associative Array
3) Multidimensional Array

4. Numeric Array
- A numeric array stores each
element with a numeric ID key.
- ways to write a numeric array.

5. Automatically
Example:
$myar = array(10,45,23,67);
$names = array(“naveed","Qamar",“Shazia");

6. Munually
Example:
$names[0] = “sofia";
$names[1] = “aysha";
$names[2] = “saif";

7. 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 strings
as keys and assign values to them.

8. The Id can be used in a script
<?php
$ages[‘Bsit’] = ”22";
$ages[‘Anwar’] = ”25";
$ages[‘Javed’] = ”26";
echo Bsit is " . $ages[‘Bsit’] . " years old.";
?>
//output
-“Bsit is 22 years old.”

9. Array functions
sort
- To sort the values of an array
$myar = array( 30,45,10,20);
Sort($myar);
Print_r($myar);
//output
Array ( [0] => 10 [1] => 20 [2] => 30 [3] => 45 )
rsort
To sort the values of an array into reverse order
$myar = array( 30,45,10,20);
Sort($myar);
Print_r($myar);
//output
Array ( [0] => 45 [1] => 30 [2] => 20 [3] => 10 )

10. asort
- To sort the values of an array, but keeping the
key/value relationships -
$myarr =
array("Mon"=>34,"Tue"=>33,"Wed"=>37,"Thr"=>40,"Fri"=>23,"Sat"=>20,"Sun"=>41);
//Out put Array
(
[Sat] => 20
[Fri] => 23
[Tue] => 33
[Mon] => 34
[Wed] => 37
[Thr] => 40
[Sun] => 41
)

11. arsort
- To sort the values of an array in descending
order, but keeping the key/value relationships -
$myarr =
array("Mon"=>34,"Tue"=>33,"Wed"=>37,"Thr"=>40,"Fri"=>23,"Sat"=>20,"Sun"=>41);
//Out put
Array
(
[Sun] => 41
[Thr] => 40
[Wed] => 37
[Mon] => 34
[Tue] => 33
[Fri] => 23
[Sat] => 20
)

12. Ksort
- To sort the elements of an array by the keys,
maintaining the key/value relationships
$myarr =
array("Mon"=>34,"Tue"=>33,"Wed"=>37,"Thr"=>40,"Fri"=>23,"Sat"=>20,"Sun"=>41);
//Out put
Array
(
[Fri] => 23
[Mon] => 34
[Sat] => 20
[Sun] => 41
[Thr] => 40
[Tue] => 33
[Wed] => 37
)

13. krsort
To sort the elements of an array by the keys,
maintaining the key/value relationships
but in descending order
$myarr =
array("Mon"=>34,"Tue"=>33,"Wed"=>37,"Thr"=>40,"Fri"=>23,"Sat"=>20,"Sun"=>41);
//Out put
Array
(
[Wed] => 37
[Tue] => 33
[Thr] => 40
[Sun] => 41
[Sat] => 20
[Mon] => 34
[Fri] => 23
)

14. 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, and so on.