Comparison is constant¶
ID: cs/constant-comparisonKind: problemSecurity severity: Severity: warningPrecision: highTags: - quality - reliability - correctnessQuery suites: - csharp-security-and-quality.qls
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Comparisons which always yield the same result are unnecessary and may indicate a bug in the logic. This can happen when the data type of one of the operands has a limited range of values. For example unsigned integers are always greater than or equal to zero, andbyte values are always less than 256.
The following expressions always have the same result:
Unsigned<0is always false,0>Unsignedis always false,0≤Unsignedis always true,Unsigned≥0is always true,Unsigned==-1is always false,Byte<512is always true.
Recommendation¶
Examine the logic of the program to determine whether the comparison is necessary. Either change the data types, or remove the unnecessary code.
Example¶
The following example attempts to count down fromnumberOfOrders to0, however the loop never terminates becauseorder is an unsigned integer and so the conditionorder>=0 is always true.
for(uintorder=numberOfOrders;order>=0;order--)ProcessOrder(order);
The solution is to change the type of the variableorder.
References¶
MSDN Library:C# Operators.