Coding pattern for random percentage branching?

Question

So let\'s say we have a code block that we want to execute 70% of times and another one 30% of times.

if(Math.random() < 0.7)
    70percentmethod();
else
         


        

Answer 1

All these answers seem quite complicated, so I'll just post the keep-it-simple alternative:

double rnd = Math.random()
if((rnd -= 0.6) < 0)
    60percentmethod();
else if ((rnd -= 0.3) < 0)
    30percentmethod();
else
    10percentmethod();

Doesn't need changing other lines and one can quite easily see what happens, without digging into auxiliary classes. A small downside is that it doesn't enforce that percentages sum to 100%.