When writing PHP applications, you may need to count files that match a filesystem glob expression. This is useful in everyday tasks such as working with imported data, application settings, user-facing lists, and reports.
The GlobIterator::count() operation provides this behavior directly. The examples below show what happens to the inputs and what to check before using the result in your application.
What Is GlobIterator::count() in PHP?
Count files that match a filesystem glob expression.
Its syntax is:
$files->count(): int
Results depend on the current filesystem. Patterns use glob matching, not regular expressions; do not assume recursive directory traversal.
Example 1: Basic Usage
Start with a small, self-contained input so you can inspect exactly how the operation behaves.
<?php
$files = new GlobIterator(__DIR__ . "/*.php");
echo $files->count();
Output: Depends on the request environment, installed extension, selected locale, or filesystem state.
Example 2: Another Important Case
This variation highlights another input shape, a comparison option, or a change in the collection.
<?php
$files = new GlobIterator(sys_get_temp_dir() . "/*.txt");
echo count($files);
Output: Depends on the request environment, installed extension, selected locale, or filesystem state.
Practical Example: Check how many export files match a trusted naming pattern before processing them
Check how many export files match a trusted naming pattern before processing them. Save the code in a PHP file and adapt the sample data to your project.
<?php
$matchingFiles = new GlobIterator(sys_get_temp_dir() . "/*.csv");
echo "Matching CSV files: " . $matchingFiles->count();
Output: Depends on the request environment, installed extension, selected locale, or filesystem state.
Important Behavior and Edge Cases
Results depend on the current filesystem. Patterns use glob matching, not regular expressions; do not assume recursive directory traversal.
- Test the operation with empty or missing input and decide how your application should respond.
- Read the return value independently from any changes to variables passed by reference.
- Validate untrusted input before using the result for permissions, database changes, or user-visible output.
Comparison With Related Functions
| Function or Approach | When to Use It |
|---|---|
GlobIterator::count() | Count files that match a filesystem glob expression |
| Related functions | glob() produces matching pathnames; FilesystemIterator supports directory traversal. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Counting nested elements as top-level elements | Understand what the collection exposes to count() and whether recursive counting is supported. |
| Assuming counting changes the items | Count only reports a number; it does not remove or consume ordinary arrays. |
| Counting a value of the wrong type | Results depend on the current filesystem. Patterns use glob matching, not regular expressions; do not assume recursive directory traversal. |
Key Takeaways
GlobIterator::count()helps you count files that match a filesystem glob expression.- Results depend on the current filesystem. Patterns use glob matching, not regular expressions; do not assume recursive directory traversal.
- glob() produces matching pathnames; FilesystemIterator supports directory traversal.
- Use the practical example as a starting point, but validate real application inputs.
GlobIterator::count() is useful when you need to count files that match a filesystem glob expression. Use its documented rules and the examples above to choose the right behavior for your data.