Search code examples
javamathpowjexl

Figure out if exponent is above long threshold before calculation

I'm using the math library in combination with the JexlEngine to calculate different equations. In this equations I also have the pow function. The problem is that when I have huge numbers like math.pow(99999, 10000), jexl tries to evaluate it and that takes a lot of time and CPU usage. The evaluation should not be done if the solution exceeds the max Long value. Is there a way to find out before evaluating the power if it is bigger then a max Long?

Solution

  • You can compare the exponent to

    double base = 99999;
double maxExp = Math.log(Long.MAX_VALUE)/Math.log(base);

    if the power is above maxExp, you will get an overflow.