How can I convert a string to uppercase in PHP? Example code:

$string = "Hello World";

echo strtoupper($string);

How can I connect to a MySQL database using PHP? Example code.

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

How can I create a multidimensional array in PHP? Example code:

How can I use the strrev function to reverse a string in PHP? Example code:

How can I use the rename function to rename a file or directory in PHP? Example code:

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

How can I use the array_intersect function to get the common elements between two or more arrays in PHP? Example code:

What is PHP code?

How can I use the array_reverse function to reverse the order of an array in PHP? Example code:

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

How can I use the array_merge function to merge two or more arrays in PHP? Example code:

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

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

How can I format a date in PHP? Example code:

How can I loop through an array in PHP? Example code

How can I use the str_replace function to replace multiple substrings in a string in PHP? Example code:

How can I use the array_search function to search for a value in an array and return its key in PHP? Example code:

How can I use the array_reduce function to apply a function to each element of an array and reduce it to a single value in PHP? Example code:

How can I use a switch statement with multiple cases in PHP? Example code:

How can I use the is_writable function to check if a file is writable 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 implode function to join an array into a string in PHP? Example code:

How can I use the array_values function to get an array of values from an associative array in PHP? Example code:

How can I subtract days from a date in PHP? Example code:

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

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

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

How can I use a regular expression to replace a pattern in a string in PHP? Example code: