The name of a variable, function, or class, should answer all the big questions. It should tell you why it exists, what it does, and how it is used. If a name requires a comment, then the name does not reveal its intent.    int d; // elapsed time in days The name d reveals nothing. It does not evoke a sense of elapsed time, nor of days. We should choose a name that specifies what is being measured and the unit of that measurement:    int elapsedTimeInDays;    int daysSinceCreation;    int daysSinceModification;    int fileAgeInDays;