Checklist for Code Reviews

There is only one purpose in the whole of life - Education.
~Swami Vivekananda

Does the code completely and correctly implement the detailed design?
Does the code conform to any pertinent coding standards?
Is the code well-structured, consistent in style, and consistently indented?
Are there any uncalled or unneeded procedures or any unreachable code?
Are there any leftover stubs or test routines in the code?
Can any code be replaced by calls to external reusable components or library functions?
Are there any blocks of repeated code that could be condensed into a single procedure?
Is storage use efficient?
Are symbolics used rather than “magic number” constants or string constants?
Are any modules excessively complex, so should be restructured or split into multiple routines?

Is the code clearly and adequately documented with an easy-to-maintain commenting style?
Are there any inconsistencies between code and comments?

Are all variables properly defined and given meaningful, consistent, and clear names?
Do all assigned variables have proper type consistency or casting?
Are there any redundant or unused variables?

Does the code avoid comparing floating-point numbers for equality?
Does the code systematically prevent rounding errors?
Does the code avoid additions and subtractions on numbers with greatly different magnitudes?
Will all mixed-mode arithmetic operations give the correct results? Are type conversions needed?

Are all loops, branches, and logic constructs complete, correct, and properly nested?
Are the most common cases tested first in IF- -ELSEIF chains?
Are all cases covered in an IF- -ELSEIF or CASE block, including ELSE or DEFAULT clauses?
In C, does the end of each case in a CASE statement have a break?
Does every switch statement have a default?
Are loop termination conditions obvious and invariably achievable?
Are indexes or subscripts properly initialized, just prior to the loop?
Can any statements that are enclosed within loops be placed outside the loops?
Does the code in the loop avoid manipulating the index variable or using it upon exit from the loop?

Are indexes, pointers, and subscripts tested against array, record, or file bounds?
Are imported data and input arguments tested for validity and completeness?
Are divisors tested for zero or noise?
Are all output variables assigned?
Are the correct data operated on in each statement?
Is every memory allocation deallocated?
Are timeouts or error traps used for external device accesses?
Are files checked for existence before attempting to access them?
Are all files and devices are left in the correct state upon program termination?