[Tim, 6/12/96:] Bug 1228227, a duplicate of this one, also points out that the
problem exists for Long.parseInt...]

java.lang.Integer.parseInt("-") returns 0 instead of throwing a
NumberFormatException. The relevant code:

    public static int parseInt(String s, int radix) throws NumberFormatException {
        if (s == null) {
            throw new NumberFormatException("null");
        }
int result = 0;
boolean negative = false;
int i=0, max = s.length();
if (max > 0) {
if (s.charAt(0) == '-') {
negative = true;
i++;
}
while (i < max) {
int digit = Character.digit(s.charAt(i++),radix);
if (digit < 0)
throw new NumberFormatException(s);
result = result * radix + digit;
}
} else
throw new NumberFormatException(s);
if (negative)
return -result;
else
return result;
    }

For a string containing just "-", negative is set to true
but the while loop is never entered. The method then returns zero.


FWIW -- the original report to java@java:

> From: ###@###.###
> Date: Tue, 14 Nov 1995 10:56:35 -0800
>
> Why following expression does not throw an exception rather it returns zero.
>
> num = Integer.parseInt("-");
>
> According to API documentation above expression should throw an exception.

The description field as copied from bug report 1232934 follows:

The call Integer.parseInt("-", 10) incorrectly returns 0.
It should throw a NumberFormatException.

There is a similar problem with Long.parseLong("-", 10).