How do I convert a String to a BigInteger?

biginteger, java, string

Solution

Using the constructor

`public BigInteger(String val)`

Translates the decimal String representation of a BigInteger into a BigInteger.

Javadoc

Problem

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);`: ``` private BigInteger sum = BigInteger.valueOf(0); private void sum(String newNumber) { // BigInteger is immutable, reassign the variable: sum = sum.add(BigInteger.valueOf(Long.parseLong(newNumber))); } ``` That works fine, but as the `BigInteger.valueOf()` only takes a `long`, I cannot add numbers greater than `long`'s max value (9223372036854775807). Whenever I try to add 9223372036854775808 or more, I get a NumberFormatException (which is completely expected). Is there something like `BigInteger.parseBigInteger(String)`?

Original source