Magic Number (ARCH6182)

Key ruby.quality.magic-number · Severity info · Category quality

Unexplained numeric literals embedded in expressions hide the code’s intent and make maintenance harder when the same value appears in several places.

Incorrect

def total_price(amount)
  amount * 1.18 + 9.90
end

Correct

VAT_RATE = 1.18
SHIPPING_FEE = 9.90

def total_price(amount)
  amount * VAT_RATE + SHIPPING_FEE
end

Fix

Extract numeric literals into named constants that explain their purpose.