In PHP, die() and exit() are functionally identical. 1. Both functions terminate script execution immediately. 2. They can accept a string message or an integer status code as an argument, where strings are outputted before termination and integers set the exit status. 3. die() is technically an alias of exit(), with the only difference being naming and perceived tone—die() seems abrupt while exit() feels more neutral and professional. 4. Usage often depends on coding style, context, or team preference, with die() commonly found in quick or older scripts and exit() preferred in larger applications or system-level scripting. 5. Neither function performs cleanup tasks like closing connections or freeing memory, and they do not throw exceptions or trigger destructors. 6. They should be used cautiously in web applications, as better alternatives like proper HTTP responses exist. 7. Consistency within a project is key, and some frameworks may discourage their use to maintain control flow.

In PHP, die() and exit() are essentially the same function — yes, really. Both stop the execution of a script immediately. You might see them used interchangeably in code, and for most practical purposes, they behave identically.

That said, there is one subtle point worth noting: die() is technically an alias of exit(). So while their behavior is identical, the name exit() might feel more formal or standard in certain coding contexts, especially when reading code written by developers who prefer clarity over brevity.

Let’s break down how each works in practice.

How Do die() and exit() Work?

Both functions terminate the script right away. You can pass them a string or an integer status code:

• If you pass a string, it will be printed to the output before stopping the script.
• If you pass an integer, it will set the exit status (which is not shown to the user but may be used by the server or shell).

Examples:

exit('Script stopped'); // Outputs "Script stopped" and stops
die(0); // Stops script with exit status 0

This is commonly used when checking for errors or conditions that should halt further processing, like missing files or invalid input.

A few common use cases:

• Stopping script after sending a custom HTTP response
• Debugging by halting at a certain point
• Preventing further execution if a required condition fails

When to Use die() vs exit()

Since they’re the same under the hood, choosing between them often comes down to coding style or team preference.

However, some trends exist:

• die() is often seen in quick-and-dirty scripts or older codebases. Its name makes it sound more abrupt — like something went wrong.
• exit() feels more neutral and professional, especially in larger applications or when returning specific status codes.

For example:

if (!file_exists('data.json')) {
    die('File not found'); // Common in simple scripts
}

// vs

if ($errorCondition) {
    exit(1); // Often used in CLI tools or system scripts
}

If you're working on a project where consistency matters, stick with whichever is already being used.

Things to Keep in Mind

While both functions do the job, here are a few details that can trip people up:

• Neither function performs any cleanup like closing database connections or freeing memory — the script just stops.
• They don't throw exceptions or trigger destructors, so use them carefully in object-oriented code.
• In web applications, avoid using these unless absolutely necessary — better practices include returning proper HTTP responses or handling errors gracefully.

Also, keep in mind that:

• Using exit or die inside a function doesn’t affect the outer scope — it still stops the whole script.
• Some frameworks or CMSs may discourage their use to maintain control flow and avoid unexpected behaviors.

So basically, there's no functional difference between die() and exit() in PHP — only naming and tone matter. Choose based on context and readability.

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