Parse String to Double with null values

Question

I have to convert Strings to Doubles, but may be I have a null value. Does it work with Double.parseDouble(stringValue) or Double.valueOf(stringValue)?

What is the difference between this two methods?

Thank you in advance.

You're asking two different questions here. One of them is a duplicate of [What is the difference between Double.parseDouble(String) and Double.valueOf(String)?](https://stackoverflow.com/questions/10577610/what-is-the-difference-between-double-parsedoublestring-and-double-valueofstr). Please restrict yourself to one question per question. — khelwood, Jan 09 '19 at 12:41

score 3 · Accepted Answer · edited Jan 12 '23 at 13:20

Neither method makes any difference. Both will throw a NullPointerExecption. Instead, you need to add a helper method which returns a Double e.g.

static Double parseDouble(String s) {
    return s == null ? null : Double.parseDouble(s);
}

or you can return a double by having a default value

static double parseDouble(String s, double otherwise) {
    return s == null ? otherwise : Double.parseDouble(s);
}

a suitable value might be Double.NaN

static double parseDouble(String s) {
    return s == null ? Double.NaN : Double.parseDouble(s);
}

Parse String to Double with null values

1 Answers1