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

Listen

if (isset($variable)) {
    echo "Variable is set";
} else {
    echo "Variable is not set";
}

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

How can I create a class in PHP? Example code:

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

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

How can I use a ternary operator in PHP? Example code:

How to create drop down menu in PHP with example

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

How can I prevent SQL injection in PHP?

How can I use the curl_setopt_array function to set multiple options for a cURL session 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 use a do-while loop in PHP? Example code:

How can I use the in_array function to check if an element exists in an array in PHP? Example code:

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

How can I send an email using PHP? Example code

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

How can I generate a random string in PHP? Example code:

How can I add days to a date in PHP? Example code:

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

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

How can I get the current date and time 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 mkdir function to create a directory in PHP? Example code:

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

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

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

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

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

How can I use the htmlentities function to convert special characters to HTML entities in PHP? Example code:

How can I use the copy function to copy a file in PHP? Example code:

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