Avoid the use of numerical values or "magic numbers" in code when possible. Appropriately named symbolic constants make code more readable rather than checks against a specific number. If clarify the intent of the programmer. In addition, if a specific number needs to be changed reassigning a symbolic value is much easier than replacing a specific number in the code because each case has to be checked specifically.
Non Compliant Code Example
| Code Block | ||
|---|---|---|
| ||
if (age >= 18) {
takevote(personID);
}
...
if (age <= 18) {
checkSchoolEnrollment(personID);
}
|
Compliant Solution
| Code Block | ||
|---|---|---|
| ||
enum { ADULT_AGE=18 };
...
if (age >= ADULT_AGE) {
takevote(personID);
}
...
if (age <= ADULT_AGE) {
checkSchoolEnrollment(personID);
}
|
...
DCL00-A. Declare immutable values using const or enum
Risk Assessment
Mistakes regarding numeric values can cause unintended consequences if changes are not made uniformly
Rule | Severity | Likelihood | Remediation Cost | Priority | Level |
|---|---|---|---|---|---|
EXP00-A | 1 (low) | 1(unlikely) | 2 (medium) | P2 | L3 |
References
Source: http://www.doc.ic.ac.uk/lab/cplus/c++.rules/chap10.html