Question

In the code below, I am getting a java.lang.NumberFormatException when entering large numbers ~1000000000. The error occurs on the second-last line -\

int integer = Integer.parseInt(split[0]);

It should work in theory since Integer type supports till 2^32-1 but it doesn’t

Scanner user_input = new Scanner(System.in);
//accept user input and convert into double
String s = user_input.next();
double number = Double.parseDouble(s);
System.out.println(number);

String answer = "";

//Split the entered number into Integer and Decimal parts
String split[] = Double.toString(number).split("\\.");
int integer = Integer.parseInt(split[0]);
int decimal = Integer.parseInt(split[1]);

Answer 1

The problem is probably because of the representation of a large double which will be in scientific notation:

1.0E9

This will mean that the split is failing, try printing out the value of the string you are parsing.

When you call toString on a double, the format used can vary, try using DecimalFormat instead:

new java.text.DecimalFormat("0.00000000").format(number)