Pattern · India 🇮🇳

Regex for JEE application number

12-digit JEE Main/Advanced application number.

The pattern

^\d{12}$

Try in explainer →

What it matches

240412345678
230456789012

What it doesn't match

12345678
1234567890123

Notes & gotchas

JEE Main application numbers are 12 digits assigned by NTA. Same format used for JEE Advanced enrollment. Mandatory for login to candidate portal, admit card download, and counselling via JoSAA.

Code in your language

Use the explainer's Code tab to generate ready-to-paste snippets in JavaScript, Python, Java, .NET, Go, Ruby, and PHP for this pattern.

Open in explainer →

About this pattern

India-specific identifiers are governed by various authorities (UIDAI for Aadhaar, Income Tax Dept for PAN, RBI for IFSC, GSTN for GSTIN, etc.). Regex confirms format; for definitive validation, integrate with the issuing authority's verification API.

Quick usage in different languages

Once you've validated a candidate value matches this pattern, you'll typically use it inside your application code. Each language has its own regex syntax:

JavaScript: new RegExp(pattern).test(value) or /pattern/.test(value)
Python: re.match(pattern, value) with raw strings: r"pattern"
Java: Pattern.compile(pattern).matcher(value).matches()
C# / .NET: Regex.IsMatch(value, pattern)
Go: regexp.MustCompile(pattern).MatchString(value) — Go uses RE2 so some advanced features aren't available
Ruby: value =~ /pattern/ or pattern.match?(value)
PHP: preg_match('/pattern/', $value)

The explainer's Code tab generates these for any pattern you paste — including the right escaping and idioms for each language.

Common pitfalls

Anchors matter. The pattern starts with ^ and ends with $ — it expects the entire input to match. To find this pattern inside a longer text, remove the anchors and use the /g flag for multiple matches.
Case sensitivity. Letter ranges like [A-Z] only match uppercase. Use the i flag or [A-Za-z] for case-insensitive matching.
Escape user input. If you're building a regex from a string variable, escape regex metacharacters first to avoid bugs or injection — use RegExp.escape-equivalents in your language.
Performance. For this specific pattern the risk is low, but be cautious of nested quantifiers when adapting it — they can cause exponential backtracking on adversarial input.