Welcome back to the PHP programming learning page. This time we will discuss arrays, more precisely arrays in PHP. Arrays in PHP are actually almost similar to arrays in javascript. But there are a few fundamental differences. For more details, please follow the tutorial article below.
PHP Array Introduction
An array stores multiple values in one single variable:
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<?php $cars = array("Volvo", "BMW", "Toyota"); echo "I like " . $cars[0] . ", " . $cars[1] . " and " . $cars[2] . "."; ?> |
What is An Array?
An exhibit is an exceptional variable, which can hold more than each incentive in turn.
On the off chance that you have a rundown of things (a rundown of vehicle names, for instance), putting away the autos in single factors could resemble this:
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$cars1 = "Volvo"; $cars2 = "BMW"; $cars3 = "Toyota"; |
Be that as it may, imagine a scenario where you need to circle through the vehicles and locate a particular one. Furthermore, imagine a scenario in which you had not 3 vehicles, however 300.
The arrangement is to make a cluster!
A cluster can hold numerous qualities under a solitary name, and you can get to the qualities by alluding to a record number.
Make an Array in PHP
In PHP, the array() work is utilized to make a cluster 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
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:
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<?php $cars = array("Volvo", "BMW", "Toyota"); echo count($cars); ?> |
PHP Indexed Arrays
There are two ways to create indexed arrays. The index can be assigned automatically (index always starts at 0), like this:
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$cars = array("Volvo", "BMW", "Toyota"); |
or the index can be assigned manually:
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$cars[0] = "Volvo"; $cars[1] = "BMW"; $cars[2] = "Toyota"; |
The accompanying model makes a recorded cluster named $cars, allots three components to it, and afterward prints a book containing the exhibit esteems:
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<?php $cars = array("Volvo", "BMW", "Toyota"); echo "I like " . $cars[0] . ", " . $cars[1] . " and " . $cars[2] . "."; ?> |
Loop Through an Indexed Array
To loop through and print every one of the estimations of a listed cluster, you could utilize a for circle, this way:
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<?php $cars = array("Volvo", "BMW", "Toyota"); $arrlength = count($cars); for($x = 0; $x < $arrlength; $x++) { echo $cars[$x]; echo "<br>"; } ?> |
PHP Associative Arrays
Affiliated clusters are exhibits that utilization named keys that you appoint to them.
There are two different ways to make an affiliated exhibit:
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$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43"); |
or :
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$age['Peter'] = "35"; $age['Ben'] = "37"; $age['Joe'] = "43"; |
The named keys can then be used in a script:
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<?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:
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<?php $age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43"); foreach($age as $x => $x_value) { echo "Key=" . $x . ", Value=" . $x_value; echo "<br>"; } ?> |
PHP Multidimensional Arrays
In the previous pages, we have described arrays that are a single list of key/value pairs.
However, sometimes you want to store values with more than one key. For this, we have multidimensional arrays.
PHP – Multidimensional Arrays
A multidimensional array is an array containing one or more arrays.
PHP supports multidimensional arrays that are two, three, four, five, or more levels deep. However, arrays more than three levels deep are hard to manage for most people.
The dimension of an array indicates the number of indices you need to select an element.
- For a two-dimensional array you need two indices to select an element
For a three-dimensional array you need three indices to select an element
PHP – Two-dimensional Arrays
A two-dimensional array is an array of arrays (a three-dimensional array is an array of arrays of arrays).
First, take a look at the following table:
| Name | Stock | Sold |
|---|---|---|
| Volvo | 22 | 18 |
| BMW | 15 | 13 |
| Saab | 5 | 2 |
| Land Rover | 17 | 15 |
We can store the data from the table above in a two-dimensional array, like this:
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$cars = array ( array("Volvo",22,18), array("BMW",15,13), array("Saab",5,2), array("Land Rover",17,15) ); |
Presently the two-dimensional $cars exhibit contains four clusters, and it has two lists: line and section.
To gain admittance to the components of the $cars cluster we should highlight the two lists (line and section):
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<?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>"; ?> |
We can also put a for loop inside another for loop to get the elements of the $cars array (we still have to point to the two indices):
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<?php for ($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>"; } ?> |
PHP Sorting Arrays
The components in a cluster can be arranged in sequential order or numerical request, plummeting or rising.
PHP – Sort Functions For Arrays
In this chapter, we will go through the following PHP array sort functions:
- sort() – sort arrays in ascending order
- rsort() – sort arrays in descending order
- asort() – sort associative arrays in ascending order, according to the value
- ksort() – sort associative arrays in ascending order, according to the key
- arsort() – sort associative arrays in descending order, according to the value
- krsort() – sort associative arrays in descending order, according to the key
Sort Array in Ascending Order – sort()
The following example sorts the elements of the $cars array in ascending alphabetical order:
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<?php $cars = array("Volvo", "BMW", "Toyota"); sort($cars); ?> |
The following example sorts the elements of the $numbers array in ascending numerical order:
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<?php $numbers = array(4, 6, 2, 22, 11); sort($numbers); ?> |
Sort Array in Descending Order – rsort()
The following example sorts the elements of the $cars array in descending alphabetical order:
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<?php $cars = array("Volvo", "BMW", "Toyota"); rsort($cars); ?> |
The following example sorts the elements of the $numbers array in descending numerical order:
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<?php $numbers = array(4, 6, 2, 22, 11); rsort($numbers); ?> |
Sort Array (Ascending Order), According to Value – asort()
The following example sorts an associative array in ascending order, according to the value:
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<?php $age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43"); asort($age); ?> |
Sort Array (Ascending Order), According to Key – ksort()
The following example sorts an associative array in ascending order, according to the key:
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<?php $age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43"); ksort($age); ?> |
Sort Array (Descending Order), According to Value – arsort()
The following example sorts an associative array in descending order, according to the value:
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<?php $age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43"); arsort($age); ?> |
Sort Array (Descending Order), According to Key – krsort()
The following example sorts an associative array in descending order, according to the key:
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<?php $age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43"); krsort($age); ?> |
Hope this article can be useful for all of us. Thank you for reading…
