I have a object which has a few base variables (integers as example) and one intermediate variable for further processing. The intermediate variable can be calculated from the base vars. Now the question: Should I always repeat the calculation of the intermediate var from the base vars or should I save the value and only change it if the base vars change? (I need access to every var in pseudo random order.)Two examples in C++-Code. Caching the result:class Test{  private:    int a;    int b;    int c;    int x;    void calcX ()    {        // Just an example for a calculation for x.        x = ((a + 10) * (b / (c*c + 1)));    }  public:    void setA (int var)    {        a = var;        calcX();    }    void setB (int var)    {        b = var;        calcX();    }    void setC (int var)    {        c = var;        calcX();    }    // Every var has a get methode.}Always recalculating the result:class Test{  private:    int a;    int b;    int c;    int x;  public:    // Var a, b and c have get and set methodes.    int getX ()    {        return ((a + 10) * (b / (c*c + 1)));    }}So, which way is considered better? I really don't know. We should not save the intermediate value because it would be redundant, but then again we should not recalculate the value again and again.
Intermediate results as variables or only base values?
c++;object oriented
It depends.If you need to calculate once, and use million times, then the answer is obvious: the first case wins.If you need to calculate every time, or quite often, then pick what you prefer. Your function doesn't read from a file, and has no slow operations, so it will not make a huge difference.Avoid premature optimization.When optimizing, it is best to measure. Profile the code and optimize only the bottlenecks. Everything else is a microoptimization, and should be avoided.