PHP arrays - Exercises, Practice, Solution
This resource offers a total of 295 PHP arrays problems for practice. It includes 59 main exercises, each accompanied by solutions, detailed explanations, and four related problems.
[An Editor is available at the bottom of the page to write and execute the scripts.]
1. Colorful Memory String
$color = array('white', 'green', 'red', 'blue', 'black');
Write a script which will display the following string -
"The memory of that scene for me is like a frame of film forever frozen at that moment: the red carpet, the green lawn, the white house, the leaden sky. The new president and his first lady. - Richard M. Nixon"
and the words 'red', 'green' and 'white' will come from $color.
2. Display Colors in Specific Format
$color = array('white', 'green', 'red'')
Write a PHP script which will display the colors in the following way :
Output :
white, green, red,
- green
- red
- white
3. Sorted Capitals from CEU Array
$ceu = array( "Italy"=>"Rome", "Luxembourg"=>"Luxembourg", "Belgium"=> "Brussels", "Denmark"=>"Copenhagen", "Finland"=>"Helsinki", "France" => "Paris", "Slovakia"=>"Bratislava", "Slovenia"=>"Ljubljana", "Germany" => "Berlin", "Greece" => "Athens", "Ireland"=>"Dublin", "Netherlands"=>"Amsterdam", "Portugal"=>"Lisbon", "Spain"=>"Madrid", "Sweden"=>"Stockholm", "United Kingdom"=>"London", "Cyprus"=>"Nicosia", "Lithuania"=>"Vilnius", "Czech Republic"=>"Prague", "Estonia"=>"Tallin", "Hungary"=>"Budapest", "Latvia"=>"Riga", "Malta"=>"Valetta", "Austria" => "Vienna", "Poland"=>"Warsaw") ;
Create a PHP script which displays the capital and country name from the above array $ceu. Sort the list by the capital of the country.
Sample Output :
The capital of Netherlands is Amsterdam
The capital of Greece is Athens
The capital of Germany is Berlin
- - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - -
4. Delete Element & Normalize Keys
$x = array(1, 2, 3, 4, 5);
Delete an element from the above PHP array. After deleting the element, integer keys must be normalized.
Sample Output :
array(5) { [0]=> int(1) [1]=> int(2) [2]=> int(3) [3]=> int(4) [4]=> int(5) }
array(4) { [0]=> int(1) [1]=> int(2) [2]=> int(3) [3]=> int(5) }
5. Get First Element from Associative Array
$color = array(4 => 'white', 6 => 'green', 11=> 'red');
Write a PHP script to get the first element of the above array.
Expected result : white
6. Decode JSON String
Write a PHP script which decodes the following JSON string.
Sample JSON code :
{"Title": "The Cuckoos Calling",
"Author": "Robert Galbraith",
"Detail": {
"Publisher": "Little Brown"
}}
Expected Output :
Title : The Cuckoos Calling
Author : Robert Galbraith
Publisher : Little Brown
7. Insert New Array Item by Position
Write a PHP script that inserts a new item in an array in any position.
Expected Output :
Original array :
1 2 3 4 5
After inserting '$' the array is :
1 2 3 $ 4 5
8. Sort Associative Array by Key and Value
Write a PHP script to sort the following associative array :
array("Sophia"=>"31","Jacob"=>"41","William"=>"39","Ramesh"=>"40") in
a) ascending order sort by value
b) ascending order sort by Key
c) descending order sorting by Value
d) descending order sorting by Key
9. Average Temperature & Extremes
Write a PHP script to calculate and display average temperature, five lowest and highest temperatures.
Recorded temperatures : 78, 60, 62, 68, 71, 68, 73, 85, 66, 64, 76, 63, 75, 76, 73,
68, 62, 73, 72, 65, 74, 62, 62, 65, 64, 68, 73, 75, 79, 73
Expected Output :
Average Temperature is : 70.6
List of seven lowest temperatures : 60, 62, 63, 63, 64,
List of seven highest temperatures : 76, 78, 79, 81, 85,
10. Bead-Sort Algorithm for Array Sorting
Write a PHP program to sort an array of positive integers using the Bead-Sort Algorithm.
According to Wikipedia "Bead-sort is a natural sorting algorithm, developed by Joshua J. Arulanandham, Cristian S. Calude and Michael J. Dinneen in 2002. Both digital and analog hardware implementations of bead sort can achieve a sorting time of O(n); however, the implementation of this algorithm tends to be significantly slower in software and can only be used to sort lists of positive integers".
Input array : Array ( [0] => 5 [1] => 3 [2] => 1 [3] => 3 [4] => 8 [5] => 7 [6] => 4 [7] => 1 [8] => 1 [9] => 3 )
Expected Result : Array ( [0] => 8 [1] => 7 [2] => 5 [3] => 4 [4] => 3 [5] => 3 [6] => 3 [7] => 1 [8] => 1 [9] => 1 )
11. Merge Arrays by Index
Write a PHP program to merge (by index) the following two arrays.
Sample arrays :
$array1 = array(array(77, 87), array(23, 45));
$array2 = array("w3resource", "com");
Expected Output :
Array ( [0] => Array ( [0] => w3resource [1] => 77 [2] => 87 ) [1] => Array ( [0] => com [1] => 23 [2] => 45 ) )
12. Change Array Values to Lower and Upper Case
Write a PHP function to change the following array's all values to upper or lower case.
Sample arrays :
$Color = array('A' => 'Blue', 'B' => 'Green', 'c' => 'Red');
Expected Output :
Values are in lower case.
Array ( [A] => blue [B] => green [c] => red )
Values are in upper case.
Array ( [A] => BLUE [B] => GREEN [c] => RED )
13. Display Numbers Divisible by 4 Without Control Statements
Write a PHP script which displays all the numbers between 200 and 250 that are divisible by 4.
Note : Do not use any PHP control statement.
Expected Output : 200,204,208,212,216,220,224,228,232,236,240,244,248
14. Get Shortest and Longest String Length from Array
Write a PHP script to get the shortest/longest string length from an array.
Sample arrays : ("abcd","abc","de","hjjj","g","wer")
Expected Output : The shortest array length is 1. The longest array length is 4.
Click me to see the solution
15. Generate Unique Random Numbers within a Range
Write a PHP script to generate unique random numbers within a range.
Sample Range : (11, 20)
Sample Output : 17 16 13 20 14 19 18 15 11 12
16. Get the Largest Key in an Array
Write a PHP script to get the largest key in an array.
Click me to see the solution
17. Lowest Non-zero Integer Function
Write a PHP function that returns the lowest integer that is not 0.
Click me to see the solution
18. Floor Decimal with Precision
Write a PHP function to floor decimal numbers with precision.
Note: Accept three parameters number, precision, and $separator
Sample Data :
1.155, 2, "."
100.25781, 4, "."
-2.9636, 3, "."
Expected Output :
1.15
100.2578
-2.964
19. Print Specific Elements from Multidimensional Array
Write a PHP script to print "second" and Red from the following array.
Sample Data :
$color = array ( "color" => array ( "a" => "Red", "b" => "Green", "c" => "White"),
"numbers" => array ( 1, 2, 3, 4, 5, 6 ),
"holes" => array ( "First", 5 => "Second", "Third"));
20. Sort Array by Priority List
Write a PHP function to sort an array according to another array acting as a priority list.
Click me to see the solution
21. Sort Subnets
Write a PHP function to sort subnets.
Click me to see the solution
22. Sort Array by Day and Username
Write a PHP script to sort the following array by the day (page_id) and username.
Click me to see the solution
23. Sort Multi-Dimensional Array by Specific Key
Write a PHP program to sort a multi-dimensional array set by a specific key.
Click me to see the solution
24. Case-Insensitive Natural Order Sorting
Write a PHP script to sort an array using case-insensitive natural ordering.
Click me to see the solution
25. Sort Entity Letters
Write a PHP function to sort entity letters.
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26. Shuffle Associative Array Preserving Keys
Write a PHP function to shuffle an associative array, preserving key, value pairs.
Click me to see the solution
27. Generate Random Password Using Shuffle
Write a PHP function to generate a random password (contains uppercase, lowercase, numeric and other) using shuffle() function.
Click me to see the solution
28. Reverse Sort Array
Write a PHP script to sort an array in reverse order (highest to lowest).
29. Array Range from String
Write a PHP program to generate an array with a range taken from a string.
Click me to see the solution
30. Create Letter Range with Arbitrary Length
Write a PHP program to create a letter range with arbitrary length.
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31. Get Index of Highest Value in Associative Array
Write a PHP program to get the index of the highest value in an associative array.
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32. Get File Extension
Write a PHP program to get the extension of a file.
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33. Search Value Within Associative Array
Write a PHP function to search a specified value within the values of an associative array.
Click me to see the solution
34. Sort Associative Array (Case-Sensitive by Values)
Write a PHP program to sort an associative array (alphanumeric with case-sensitive data) by values.
Click me to see the solution
35. Trim All Array Elements Using array_walk
Write a PHP script to trim all the elements in an array using array_walk function.
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36. Convert Array Elements to Lower and Upper Case
Write a PHP script to lower-case and upper-case, all elements in an array.
Click me to see the solution
37. Count Occurrences of a Specific Value in Array
Write a PHP script to count the total number of times a specific value appears in an array.
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38. Multidimensional Unique Array by Key Index
Write a PHP function to create a multidimensional unique array for any single key index.
Click me to see the solution
39. Remove Duplicate Values from Array
Write a PHP program to remove duplicate values from an array which contains only strings or only integers.
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40. Sorted Array Without Preserving Keys
Write a PHP program to get a sorted array without preserving the keys.
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41. Identify Non-Unique Email Addresses
Write a PHP program to identify the email addresses which are not unique.
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42. Unique Flattened Values from Multidimensional Arrays
Write a PHP function to find unique values from multidimensional arrays and flatten them in zero depth.
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43. Merge Two Comma-Separated Lists with Unique Values
Write a PHP script to merge two commas separated lists with unique value only.
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44. Remove Specified Duplicate Entry from Array
Write a PHP a function to remove a specified, duplicate entry from an array.
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45. Multi-Dimensional Array Difference using array_udiff
Write a PHP script to do a multi-dimensional difference, i.e. returns values of the first array that are not in the second array.
Note : Use array_udiff() function.
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46. Check if All Array Values Are Strings
Write a PHP function to check whether all array values are strings or not.
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47. Get an Array with First Key and Value
Write a PHP function to get an array with the first key and value.
48. Set Union of Two Arrays
Write a PHP function to set union of two arrays.
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49. Get Array Entries with Specific Keys
Write a PHP script to get an array containing all the entries of an array which have the keys that are present in another array.
Test Data :
1st array : ('c1' => 'Red', 'c2' => 'Green', 'c3' => 'White', c4 => 'Black')
2nd array : ('c2', 'c4')
Output :
Array
(
[c2] => Green
[c4] => Black
)
50. Get Last Array Value Without Affecting Pointer
Write a PHP script to get the last value of an array without affecting the pointer.
Click me to see the solution
51. Filter Out Elements with Certain Key-Names
Write a PHP program to filter out some elements with certain key-names.
Test Data :
1st array : ('c1' => 'Red', 'c2' => 'Green', 'c3' => 'White', c4 => 'Black')
2nd array : ('c2', 'c4')
Output :
Array
(
[c1] => Red
[c3] => White
)
52. Filter a Multi-Dimensional Array by Value
Write a PHP function to filter a multi-dimensional array. The function will return those items that will match with the specified value.
Click me to see the solution
53. Delete Specific Value Using array_filter
Write a PHP script to delete a specific value from an array using array_filter() function.
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54. Remove All White Spaces in Array
Write a PHP script to remove all white spaces in an array.
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55. Convert String to Array (Trim and Remove Empty Lines)
Write a PHP function to convert a string to an array (trimming every line and remove empty lines).
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56. Create Two-Dimensional Array (4x4) Initialized to 10
Write a PHP script to create a two-dimensional array (4x4), initialized to 10.
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57. Compare Two Multidimensional Arrays for Difference
Write a PHP function to compares two multidimensional arrays and returns the difference.
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58. Combine Two Arrays (Keys and Values)
Write a PHP script to combine (using one array for keys and another for its values) the following two arrays.
('x', 'y', 'y'), (10, 20, 30)
Click me to see the solution
59. Create a Range-Like Array from a String
Write a PHP program to create a range like the following array.
Array
(
[20] => 2
[21] => 3
[22] => 4
[23] => 5
[24] => 6
[25] => 7
)
PHP Code Editor:
More to Come !
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