Cron Step Value Extraction Regex for JavaScript

What this pattern does

This page provides a well-structured, multi-part regular expression for matching cron step value extraction, ported and verified for JavaScript. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

// Cron Step Value Extraction
// ReDoS-safe | RegexVault — Dev & Systems > Cron

const cronStepValueExtractionRegex = /(?:\*|[0-9]{1,2}(?:-[0-9]{1,2})?)\/([1-9][0-9]?)/g;

function validateCronStepValueExtraction(input: string): boolean {
  return cronStepValueExtractionRegex.test(input);
}

// Example
console.log(validateCronStepValueExtraction("*/15")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Dev & Systems > Cron category and carries a ReDoS-safe certification. That matters for JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Capture group 1 contains the step value. Used for programmatic extraction of schedule frequency. A step must always follow either * or a range.