Back
Syntax
Study
Editor
Mode:
HTML
CSS
JavaScript
PHP
Reset
Run »
HTML / CSS / JS
// Use verbose mode in other languages (JS lacks it, but comment inline) // Validate ISO date: YYYY-MM-DD const ISO_DATE = /^(?<year>\d{4})-(?<month>0[1-9]|1[0-2])-(?<day>0[1-9]|[12]\d|3[01])$/; // Test your regex against: // 1. Valid inputs // 2. Near-miss inputs (wrong format) // 3. Empty string // 4. Extremely long strings // 5. Unicode characters // Use named groups for readability // Prefer \d over [0-9] for brevity // Use anchors ^ and $ for full-string validation
Result
Open