Chapter 1: Deffensive programming

• Assume nothing. Unwritten assumptions continually cause faults, particularly as code grows.
• Employ a Good Coding Style and Sound Design
• Don’t Code in a Hurry
• Trust no one. Absolutely anyone—including yourself—can introduce flaws into your program logic. Treat all inputs and all results with suspicion until you can prove that they are valid.
• Write Code for Clarity, Not Brevity
• Keep it simple (KISS)
• If it can’t be maintained, your code is not safe.
• Simplicity is a virtue. Never make code more complex than necessary.
• Compile with All Warnings Switched On: Compiler warnings catch many silly coding errors. Always enable them. Make sure your code compiles silently.
• Use Static Analysis Tools
• Use Safe Data Structures
• Check Every Return Value
• Handle Memory (and Other Precious Resources) Carefully
• Treat all scarce resources with respect. Manage their acquisition and release carefully.
• Initialize All Variables at Their Points of Declaration
• Declare Variables as Late as Possible: and do not use the same variable for sematically different way.
• Use a Good Diagnostic Logging Facility
• Providing default behavior, especially if it is erroneouse.
• Checking numeric limits
• Make everything as const as you possibly can (final, in java)
• Make Preconditions, postconditions, invariants, assertions