Code Quality

Dead Code in JavaScript: How to Find and Eliminate It

Dead code includes unreachable code after return statements, unused variables, and feature flags permanently set to false. It increases bundle size and confuses developers.

❌ Dead Branch and Unreachable Code

function processPayment(amount, method) {
  if (method === 'cash') {
    return processCash(amount);
    console.log('Cash processed');  // Unreachable!
  }
  if (false) {  // Dead branch
    chargeCard(amount);
  }
  return processCard(amount);
}

✅ Cleaned Up

function processPayment(amount, method) {
  if (method === 'cash') {
    return processCash(amount);
  }
  return processCard(amount);
}

💡

Pro tip: Enable ESLint's no-unreachable and no-constant-condition rules. Run webpack-bundle-analyzer to find dead code in production bundles.

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Dead Code in JavaScript: How to Find and Eliminate It

❌ Dead Branch and Unreachable Code

✅ Cleaned Up

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