File Extension Regex Pattern
Extracts file extensions from filenames. Simple pattern for file type checking in upload forms.
Live Regex Tester
Pattern Breakdown
Code Examples
JavaScript
const regex = /\.(\w{1,10})$/;
const test = "document.pdf";
console.log(regex.test(test)); // true
// Extract matches
const matches = test.match(regex);
console.log(matches);Python
import re
pattern = r'\.(\w{1,10})$'
test = "document.pdf"
match = re.search(pattern, test)
print(match) # Found!Go
package main
import (
"fmt"
"regexp"
)
func main() {
re := regexp.MustCompile(`\.(\w{1,10})$`)
fmt.Println(re.MatchString("document.pdf")) // true
}Common Use Cases
Match Examples
| Input | Result |
|---|---|
| document.pdf | Match |
| noextension | No Match |
About the File Extension Regex
Extracts file extensions from filenames. Simple pattern for file type checking in upload forms.
Regular expressions (regex) are powerful pattern matching tools used across virtually all programming languages. The file extension pattern is classified as beginner difficulty in the file & path category. It works in all major programming languages.
When using this regex, always consider edge cases and test thoroughly with real-world data. Use the interactive tester above to validate the pattern against your specific inputs before deploying to production.
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Frequently Asked Questions
What is the File Extension regex pattern?
Extracts file extensions from filenames. Simple pattern for file type checking in upload forms.
How do I use the File Extension regex?
Use the pattern /\.(\w{1,10})$/ in your code. In JavaScript: new RegExp('\.(\w{1,10})$', ''). Test it above with your own input.
What does this File Extension regex match?
This pattern matches: "document.pdf". It does NOT match: "noextension". File type detection, upload validation, file sorting.
Is the File Extension regex beginner-friendly?
This pattern is rated Beginner. It uses basic regex syntax and is easy to understand.
What languages support the File Extension regex?
This pattern works in all major programming languages including JavaScript, Python, Java, C#, Go, Ruby, PHP, and more. Syntax may vary slightly between regex engines.
Can I modify the File Extension regex for my use case?
Yes! Use the interactive tester above to modify the pattern and test with your own data. Common modifications include making it case-insensitive (add 'i' flag), matching globally (add 'g' flag), or adjusting character classes.