Percentage Regex Pattern
Matches percentage values with optional decimal places and negative sign, requiring the percent symbol at the end.
Live Regex Tester
Pattern Breakdown
Code Examples
JavaScript
const regex = /^-?\d+(\.\d+)?%$/; const test = "99.9%"; console.log(regex.test(test)); // true // Extract matches const matches = test.match(regex); console.log(matches);
Python
import re pattern = r'^-?\d+(\.\d+)?%$' test = "99.9%" match = re.search(pattern, test) print(match) # Found!
Go
package main
import (
"fmt"
"regexp"
)
func main() {
re := regexp.MustCompile(`^-?\d+(\.\d+)?%$`)
fmt.Println(re.MatchString("99.9%")) // true
}Common Use Cases
Match Examples
| Input | Result |
|---|---|
| 99.9% | Match |
| 100 | No Match |
About the Percentage Regex
Matches percentage values with optional decimal places and negative sign, requiring the percent symbol at the end.
Regular expressions (regex) are powerful pattern matching tools used across virtually all programming languages. The percentage pattern is classified as beginner difficulty in the numbers category. It works in all major programming languages.
When using this regex, always consider edge cases and test thoroughly with real-world data. Use the interactive tester above to validate the pattern against your specific inputs before deploying to production.
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Frequently Asked Questions
What is the Percentage regex pattern?
Matches percentage values with optional decimal places and negative sign, requiring the percent symbol at the end.
How do I use the Percentage regex?
Use the pattern /^-?\d+(\.\d+)?%$/ in your code. In JavaScript: new RegExp('^-?\d+(\.\d+)?%$', ''). Test it above with your own input.
What does this Percentage regex match?
This pattern matches: "99.9%". It does NOT match: "100". Data validation, statistics, report parsing.
Is the Percentage regex beginner-friendly?
This pattern is rated Beginner. It uses basic regex syntax and is easy to understand.
What languages support the Percentage 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 Percentage 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.