Question

If I use compareTo an a BigInteger, how can I choose from the outcome which function to call? (-1 = funcA, +1 = funcB, 0 = no function).

Especially: what’s wrong with this?

doCompare() {
   BigInteger x = new BigInteger(5);
   BigInteger y = new BigInteger(10);

   //syntax error token "<", invalid assignment operator
   x.compareTo(y) < 0 ? funcA() : funcB();
}

void funcA();
void funcB();

Answer 1

First of all, you are using BigInteger() constructor incorrectly, it takes String not int or long. And your functions must have boolean return type, otherwise you cannot use them in ternary operation.

   void doCompare() 
    {
       BigInteger x = new BigInteger("5");
       BigInteger y = new BigInteger("10");

       boolean result = x.compareTo(y) < 0 ? funcA() : funcB();
    }

    boolean funcA(){return true;};
    boolean funcB(){return false;};