Don't Repeat Yourself (DRY)

Research Finding:
The DRY principle: Don't Repeat Yourself.

IfSQ Defect Indicators based on this finding:

• SPM-1—Magic Numbers
  Numeric literals (other than 0 or 1) have been hard-coded into the program.
• SPM-2—Magic Strings
  A string literal has been hard-coded into a statement that influences the flow of a program.
• SPM-3—Copy/Paste Programming
  An identical or largely similar section of code appears in two or more places in a program or set of programs. Copy and Paste is considered by many industry experts to be a design error.

Source:

The Pragmatic Programmer

• Andrew Hunt, and David Thomas
• Published 2000 by Addison Wesley