How can PHP itself be used as a debugger while working on a script?

PHP itself can be used as a debugger by utilizing functions like `var_dump()`, `print_r()`, and `die()`. These functions can help output variable values, arrays, or objects at various points in the script to track the flow of data and identify any issues. By strategically placing these debugging functions in the code, developers can effectively troubleshoot and pinpoint errors.

// Example of using var_dump() to debug a variable
$variable = "Hello, world!";
var_dump($variable);