java convert to int

Question

I am trying to convert to int like this, but I am getting an exception.

    String strHexNumber = "0x1";
    int decimalNumber = Integer.parseInt(strHexNumber, 16);
    Exception in thread "main" java.lang.NumberFormatException: For input string: "0x1"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Integer.parseInt(Integer.java:458)

It would be a great help if someone can fix it.

Thanks.

Answer 1

That's because the 0x prefix is not allowed. It's only a Java language thing.

String strHexNumber = "F777";
int decimalNumber = Integer.parseInt(strHexNumber, 16);
System.out.println(decimalNumber);

If you want to parse strings with leading 0x then use the .decode methods available on Integer, Long etc.

int value = Integer.decode("0x12AF");
System.out.println(value);