When a PHP application needs to uses filemtime to process its supported input, choosing the right API and checking its results helps keep code understandable and dependable. This guide explains filemtime with focused examples and important details.
What Is filemtime in PHP?
filemtime uses filemtime to process its supported input. Use clearstatcache() if the file changed during the request, and check for false.
Syntax:
filemtime(filename) : int|falseParameters and return value: Parameters: <required> string $filename. Check the return value or modified object rather than assuming the operation always succeeds.
Important: The code examples use representative input rather than production credentials. Confirm that the required PHP extension is installed.
Example 1: Basic Usage
Start with a compact input so the main operation is visible.
<?php
echo filemtime(__FILE__);
Uses filemtime to process its supported input. Use clearstatcache() if the file changed during the request, and check for false.
Example 2: A Different Input
The next example changes the input or option to illustrate another behavior.
<?php
print_r(date("c", filemtime(__FILE__)));
Compare this result with the first example. Use clearstatcache() if the file changed during the request, and check for false.
Practical Example: Applying the Function
This example combines the API with a realistic processing step and shows where to check its result.
<?php
$path = __FILE__;
clearstatcache(true, $path);
if (is_file($path)) { echo date("Y-m-d H:i", filemtime($path)); }
Adapt the inputs to your application and validate the output before storing or displaying it. Use clearstatcache() if the file changed during the request, and check for false.
Important Behavior and Edge Cases
- Main purpose: Uses filemtime to process its supported input.
- Errors and boundaries: Use clearstatcache() if the file changed during the request, and check for false.
- Environment: The code examples use representative input rather than production credentials. Confirm that the required PHP extension is installed.
Comparison With Related Functions
| Function or Approach | When to Use It |
|---|---|
filemtime | Uses filemtime to process its supported input. |
| Related PHP functions | Consider this alternative when you need different behavior or a different abstraction. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Assuming the operation succeeds for every input | Use clearstatcache() if the file changed during the request, and check for false. |
| Ignoring runtime requirements or variable output | The code examples use representative input rather than production credentials. Confirm that the required PHP extension is installed. |
| Using the wrong API for the goal | Compare filemtime with Related PHP functions before selecting an approach. |
Key Takeaways
- Uses filemtime to process its supported input.
- Use clearstatcache() if the file changed during the request, and check for false.
- The code examples use representative input rather than production credentials. Confirm that the required PHP extension is installed.
Use filemtime when you need to uses filemtime to process its supported input. The three examples move from a simple call to a practical use. Validate all external input and handle failures explicitly.