java - What does ceill floor in this code mean? -

can explain me code mean? in if/else. have read documentation several times, can't these functions mean. thanks.

private long getbalancewithfactor(long balance, double factor) {         double faccountbalance = (double)balance * factor;         long res = 0;         if ((math.ceil(faccountbalance) - faccountbalance) <= 0.5)             res = (long)math.ceil(faccountbalance);         else             res = (long)math.floor(faccountbalance);         return res;     } 

math.ceil() rounds up, math.floor() rounds down nearest integer.

so example if give 0.5

ceil(0.5) return 1.0, , floor(0.5) return 0.0.

there useful function in context: math.round() ceil() , floor() combined. rounds nearest integer using mathematical rounding rules.

please note these methods return doubles you'll need cast them integers.