PHP Arrays

An array is a single variable that holds numerous values of same datatype.

An array is a type of variable that may hold several values at the same time.

If you have a list of objects (for example, a list of vehicle names), it may look like this when saving vehicles into individual variables.

$cars1 = "Volvo";
$cars2 = "BMW";
$cars3 = "Toyota";

But what if you want to search through all of the automobiles to find a specific one? What if you had 300 cars instead of three?

To solve the problem, make an array!

An array may have numerous values in one name, and by reference to an index number, you may retrieve the data.

The array() function in PHP is used to generate an array.

array(list_of_values);

Note:- Each value seperated by comma (,) in the list.

Example :-

<?php
$colors = array("Red", "Green", "Blue");
echo "I like " . $colors[0] . ", " . $colors[1] . " and " . $colors[2] . ".";
?>

Output :-

In PHP, there are three types of arrays:

• Indexed arrays - Arrays that have a number index.
• Associative arrays - Arrays containing names for the keys.
• Multidimensional arrays - Arrays that are made up of one or more arrays.

The length (number of entries) of an array is returned by the count() method.

Example :-

<?php
$colors = array("Red", "Green", "Blue");
echo "Total colors :- " . count($colors);
?>

Output :-

There are two ways to create indexed arrays:

$cars = array("Volvo", "BMW", "Toyota");

or the index can be assigned manually :

$cars[0] = "Volvo";
$cars[1] = "BMW";
$cars[2] = "Toyota";

A for loop, such as this one, might be used to cycle through and output all the values of an indexed array.

Example :-

<?php
$cars = array("Volvo", "BMW", "Toyota");
$length = count($cars);
for($x = 0; $x < $length; $x++) {
  echo $cars[$x];
  echo "<br />";
}
?>

Output :-

Associative arrays are those that employ named keys that you provide.

Unlike an indexed array, it will not support index number of the element to access the array element.

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";

Example :- The named keys can then be used in a script :

<?php
$age = array("Peter"=>"35", "Joe"=>"43");
echo "Peter is " . $age['Peter'] . " years old.";
echo "Joe is " . $age['Joe'] . " years old.";
?>

Output :-

You might use a foreach loop, like this, to cycle over and output all of the values in an associative array.

Example :-

<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
foreach($age as $key_name => $key_value) {
  echo "Key = " . $xkey_name . ", Value = " . $key_value;
  echo "<br />";
}
?>

Output :-

You may want to save values with several keys on occasion. We use multidimensional arrays for this.

An array comprising one or more arrays is called a multidimensional array.

PHP supports two, three, four, five, and deeper multidimensional arrays. Arrays deeper than three levels for most individuals never the less are difficult to handle.

One array's dimension shows how many indices are required to pick an element.

• To choose an element from a two-dimensional array, you'll need two indices.
• To choose an element from a three-dimensional array, you'll need three indices.

An array of arrays makes up a two-dimensional array (An array of arrays makes up a three-dimensional array)

before that, just look at the below table :

The data from the previous table may be stored in a two-dimensional array, as seen below.

$cars = array (
  array("Volvo",22,18),
  array("BMW",15,13),
  array("Saab",5,2),
  array("Land Rover",17,15)
);

There are now four arrays in the $cars double-dimensional array with two indications : row and column.

Example 1 :-

We have to point to two indices (row and column) to obtain access to $cars elements :

<?php
echo $cars[0][0].": In stock: ".$cars[0][1].", sold: ".$cars[0][2].".<br />";
echo $cars[1][0].": In stock: ".$cars[1][1].", sold: ".$cars[1][2].".<br />";
echo $cars[2][0].": In stock: ".$cars[2][1].", sold: ".$cars[2][2].".<br />";
echo $cars[3][0].": In stock: ".$cars[3][1].", sold: ".$cars[3][2].".<br />";
?>

Output :-

Example 2 :-

In another for a loop we can additionally place one for loop to obtain the $cars array items (we still have two indexes to point out):

<?php
for ($row = 0; $row < 4; $row++) {
  echo "<p><b>Row number $row</b></p>";
  echo "<ul>";
  for ($col = 0; $col < 3; $col++) {
    echo "<li>".$cars[$row][$col]."</li>";
  }
  echo "</ul>";
}
?>

Output :-

The components in a table can be sorted by descending or ascending, in alphabetical or numerical format.

We'll go over the PHParray sort functions in this chapter :

• sort() - Ascending order of sort arrays.
• rsort() - Descending order of sort arrays.
• asort() - Associative arrays should be sorted in ascending order by value..
• ksort() - Associative arrays should be stored in ascending order by key..
• arsort() - Associative arrays should be stored in descending order by value.
• krsort() - Associative arrays should be stored in descending order order by key.

The sort() function is used to sorting in ascending order of an given indexed array.

Example 1 :- The items of the $cars array are sorted in ascending alphabetical order in the example below :

<?php
$cars = array("Volvo", "BMW", "Toyota");
sort($cars);
?>

Output :-

Example 2 :- This example arranges $numbers in ascending numerical order : The following items are :

<?php
$numbers = array(4, 6, 2, 22, 11);
sort($numbers);
?>

Output :-

The rsort() function is used to sorting in descending order of an given indexed array.

Example 1 :- In descending alphabetical order, this example sorts the members of the $cars array :

<?php
$cars = array("Volvo", "BMW", "Toyota");
rsort($cars);
?>

Output :-

Example 2 :- The items of the $numbers array are sorted in decreasing numerical order in the example below :

<?php
$numbers = array(4, 6, 2, 22, 11);
rsort($numbers);
?>

Output :-

The asort() function is used to sort an associative array in ascending order based on array value.

Example :- In ascending order, the following example sorts a group array according to the value :

<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
asort($age);
?>

Output :-

The ksort() function is used to sort an associative array in ascending order based on array keys.

Example :-

The example below specifies an associative array in ascending order based on the key :

<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
ksort($age);
?>

Output :-

Example :- In descending order, according to value, the following example sorts an associated array:

<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
arsort($age);
?>

Output :-

Example :- The example below sorts an associative array in decreasing order based on the key :

<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
krsort($age);
?>

Output :-