How do I convert a String to a BigInteger?

Question

I\'m trying to read some really big numbers from standard input and add them together.

However, to add to BigInteger, I need to use BigInteger.valueOf(long);

Answer 1

BigInteger has a constructor where you can pass string as an argument.

try below,

private void sum(String newNumber) {
    // BigInteger is immutable, reassign the variable:
    this.sum = this.sum.add(new BigInteger(newNumber));
}