What are some best practices for handling errors and accessing variables within custom PHP functions?

When handling errors in custom PHP functions, it is important to use try-catch blocks to catch any exceptions that may occur. Additionally, accessing variables within functions should be done using parameters passed into the function rather than relying on global variables. This helps to encapsulate the function and make it more reusable and easier to debug.

function customFunction($variable) {
    try {
        // code that may throw an exception
    } catch (Exception $e) {
        // handle the exception
    }
    
    // access the variable passed into the function
    echo $variable;
}

// call the function with the variable
customFunction($myVariable);