The ‘rsort’ function can be used to check if an array is multidimensional or not. It takes one parameter, i.e the array that needs to be checked and returns yes or no depending on the nature of the array.Example Live DemoOutputIs the array multi-dimensional? bool(true)An array is defined that contains string elements. A function named ‘multi_dim’ is defined that sorts the elements of the array using ‘rsort’. The ‘isset’ function is then used to perform ‘AND’ operation on the elements of the array. This would help understand if the array has a single dimension or is multi-dimensional.Read More

Using the ‘sizeof’ functionLet us see an example −Example Live DemoOutputThe array is empty!An array can be checked to see if it is empty or not in multiple ways. One method is to use the ‘sizeof’ function that sees if the array is empty. If yes, the size would be 0, thereby confirming the array being empty.Using the ‘empty’ functionExample Live DemoOutputThe array is non-empty The array is empty!Another method to check if an array is empty or not is to use the ‘empty’ function, that checks to see the contents of the array, and if nothing is present, says it is ... Read More

To remove empty array elements in PHP, the code is as follows −Example Live DemoOutputAfter removing null values from the array, the array has the below elements -This 91 102 is a sampleAn array is defined, that contains strings, numbers and ‘null’ values. The ‘foreach’ loop is used to iterate over the elements and if a value is empty, i.e. it contains null, then it is deleted from the array. The relevant array is displayed again that wouldn’t contain null values.

To merge duplicate values into multi-dimensional array in PHP, the code is as follows −Example Live DemoOutputThe unique array elements are Array (    [Cycling] => Array    (       [0] => Array       (          [Age] => 23          [name] => Joe          [hobby] => Cycling       )       [1] => Array       (          [Age] => 30          [name] => Dev          [hobby] => Cycling       ) ... Read More

The ‘array_flip’ function can be used, that will reverse the values as indices and keys as values.Example Live DemoOutputThe original array contains Array (    [0] => 45    [1] => 65    [2] => 67    [3] => 99    [4] => 81    [5] => 90    [6] => 99    [7] => 45    [8] => 68 ) The array after removing duplicate elements is Array (    [0] => 45    [1] => 65    [2] => 67    [3] => 99    [4] => 81    [5] => 90    [6] => 68 )An array ... Read More

The ‘array_diff’ function can be used to find the elements that are missing from the array.Example Live DemoOutputElements missing from first array are Array (    [1] => 46    [2] => 47    [4] => 49    [5] => 50    [9] => 54    [10] => 55 ) Elements missing from second array are Array (    [1] => 100    [3] => 102    [4] => 103 )A function named ‘absent’ is defined that checks to see the minimum number and the maximum number and generates an array within that range. The function then returns the difference between this array and the original array, using the ‘array_diff’ function, that gives the missing elements from the array.

To find standard deviation of values within an array, the code is as follows in PHP −Example Live DemoOutputThe standard deviation of elements in the array is 35.423156268181A function named ‘std_deviation’ is defined counts the number of elements in the array and initializes the variance to 0. The average is calculated as the sum of elements in the array divided by the total number of elements in the array. Now, a ‘foreach’ loop is run over the array and the variance is calculated by subtracted the average value from every element of the array and squaring it.When the foreach loop goes ... Read More

The header function in PHP can be used to redirect the user from one page to another. It is an in-built function that sends raw HTTP header to the destination (client).Syntax of header functionheader( $header_value, $replace_value, $http_response_code)Following are the parameters −The ‘header_value’ in the function is used to store the header string.The ‘replace_value’ parameter stores the value that needs to be replaced.The ‘response_code’ is used to store the HTTP response code.ExampleThe website to which the page needs to be redirected is specified in the header function.

The ‘foreach’ loop in PHP helps in accessing key value pairs within an array. The ‘foreach’ loop works with arrays only, with the advantage that a loop counter wouldn’t need to be initialized. In addition to this, no condition needs to be set that would be needed to exit out of the loop. The ‘foreach’ loop implicitly does this too.Example Live DemoOutputJoe Hannah Paul SannaAn array of string values is defined and the foreach loop is used to access every element inside the array by giving a variable name. The ‘echo’ is used to display every element of the array on ... Read More

The ‘unset’ function can be used to remove an element from the array and use the ‘array_values’ function that resets the indices of the array.Example Live DemoOutputThe array is array(5) {    [0]=>    string(4) "this"    [1]=>    string(2) "is"    [2]=>    string(1) "a"    [3]=>    string(6) "sample"    [4]=>    string(4) "only" } The array is now array(4) {    [0]=>    string(4) "this"    [1]=>    string(2) "is"    [2]=>    string(1) "a"    [3]=>    string(6) "sample" }An array is declared that contains string values. The array is displayed and the ‘unset’ function is used to delete a specific index element from the array. Then the array is displayed again to reflect the changes on the console.