How can I use the implode function to join an array into a string with a separator in PHP? Example code:

$fruits = array("apple", "banana", "orange");

$string = implode(" | ", $fruits);

echo $string;

How can I use the array_filter function to filter an array based on a condition in PHP? Example code:

How can I use the array_shift function to remove the first element from an array in PHP? Example code:

How can I read data from a JSON file using PHP? Example code:

How can I use a for loop in PHP? Example code:

How can I use the mkdir function to create a directory in PHP? Example code:

How can I use the is_readable function to check if a file is readable in PHP? Example code:

How can I use the array_map function to apply a function to each element of an array in PHP? Example code:

How can I calculate the sum of an array in PHP? Example code:

How can I use the fopen and fwrite functions to write a string to a file in PHP? Example code:

How can I use the array_unique function to remove duplicate elements from an array in PHP? Example code:

How can I replace a substring in a string in PHP? Example code:

How can I use the array_unshift function to add an element to the beginning of an array in PHP? Example code:

How can I check if a variable is set in PHP? Example code:

How can I read a file in PHP? Example code:

How can I create a session variable in PHP? Example code

How can I write to a CSV file in PHP? Example code:

How can I read a CSV file in PHP? Example code:

How can I use the file_get_contents function to read the contents of a file into a string in PHP? Example code:

How can I use a do-while loop in PHP? Example code:

How can I calculate the difference between two dates in PHP? Example code:

How can I use the array_chunk function to split an array into chunks in PHP? Example code:

How can I use the glob function to get a list of files that match a pattern in PHP? Example code:

How can I use the array_splice function to remove and replace elements in an array in PHP? Example code:

How can I sort an array in PHP? Example code:

How can I use the json_encode function to convert an array or object to a JSON string in PHP? Example code:

How can I retrieve data from a MySQL database using PHP? Example code

How can I prevent SQL injection in PHP?

How can I use an elseif statement in PHP? Example code:

How can I use the curl_setopt function to set options for a cURL session in PHP? Example code:

How can I check if a string ends with a certain substring in PHP? Example code: