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

Listen

$file = "/path/to/file.txt";

if (is_writable($file)) {
    echo "The file is writable";
} else {
    echo "The file is not writable";
}

How can I use a while loop 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 curl_exec function to execute a cURL session and get the response in PHP? Example code:

How can I use the explode function to split a string into an array in PHP? Example code:

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

How can I validate a form using PHP? Example code

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

How can I use a try-catch block in PHP? Example code:

How can I use the scandir function to get a list of files and directories in 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 filemtime function to get the last modified time of a file 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 read a file in PHP? Example code:

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

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

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

How can I get the current date and time in PHP? Example code:

How can I use the curl_init function to initialize a cURL session in PHP? Example code:

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

How can I trim whitespace from the beginning and end of a string in PHP? Example code:

How can I use the array_slice function to get a portion of an array in PHP? Example code:

How can I sort an associative array by its values in PHP? Example code:

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

How can I use a conditional statement in PHP? Example code

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

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

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

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

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

How can I use the fopen and fgets functions to read a file line by line in PHP? Example code: