Panic in PHP

In PHP, we don’t have a direct equivalent to Go’s panic. However, we can use exceptions to achieve similar behavior. Here’s how we might translate the concept:

<?php

// We'll use exceptions throughout this site to check for
// unexpected errors. This is the only program on the
// site designed to throw an exception.
throw new Exception("a problem");

// A common use of exceptions is to abort if a function
// returns an error value that we don't know how to
// (or want to) handle. Here's an example of
// throwing an exception if we get an unexpected error when creating a new file.
try {
    $file = fopen("/tmp/file", "w");
    if ($file === false) {
        throw new Exception("Failed to create file");
    }
} catch (Exception $e) {
    // In a real application, you might want to log the error or handle it more gracefully
    die("An error occurred: " . $e->getMessage());
}

Running this program will cause it to throw an exception, print an error message, and exit with a non-zero status.

When the first exception in the script is thrown, the program exits without reaching the rest of the code. If you’d like to see the program try to create a temp file, comment out the first exception.

$ php panic.php
PHP Fatal error:  Uncaught Exception: a problem in /path/to/panic.php:5
Stack trace:
#0 {main}
  thrown in /path/to/panic.php on line 5

Note that unlike some languages which use exceptions for handling of many errors, in PHP it’s common to use a mix of error-indicating return values and exceptions. Exceptions are typically used for exceptional circumstances rather than for normal error handling.

In PHP, you can use set_exception_handler() to define a global exception handler that will be called when an uncaught exception occurs. This can be useful for logging errors or performing cleanup operations before the script terminates.

<?php

set_exception_handler(function($e) {
    echo "Uncaught exception: " , $e->getMessage(), "\n";
});

throw new Exception("This will be caught");

echo "This line will never be executed";

This script will output:

Uncaught exception: This will be caught

Remember that while exceptions can be useful for handling exceptional circumstances, it’s generally better to anticipate and handle potential errors gracefully where possible.