How can the success or failure of a function be determined in PHP?

To determine the success or failure of a function in PHP, you can use the `return` statement to explicitly return a value indicating success or failure. Typically, functions return `true` on success and `false` on failure. You can then check the return value of the function call to determine its outcome.

function myFunction() {
    // perform some operation
    if ($operation_successful) {
        return true; // return true on success
    } else {
        return false; // return false on failure
    }
}

// Call the function and check its return value
if (myFunction()) {
    echo "Function executed successfully.";
} else {
    echo "Function failed to execute.";
}