Converting 0x1 to 1 in java

Question

0x1 is the hexadecimal form of 1. More information is in this link.
I'm trying to convert that 0x1 into 1. So I'm using this code.

    String hex = "0x1";
    int decimal = Integer.parseInt(hex, 16);
    System.out.println(decimal);

However, it returns exception as

Exception in thread "main" java.lang.NumberFormatException: For input string: "0x1"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at HelloWorld.main(HelloWorld.java:7)

How can I make this java code print 1?

You could skip the first two characters. `int decimal = Integer.parseInt(hex.substring(2), 16);` — Elliott Frisch, Jul 01 '21 at 04:30

score 2 · Accepted Answer · answered Jul 01 '21 at 04:30

You can use Integer.decode:

String hex = "0x1";
int value = Integer.decode(hex);
System.out.println(value);

(Note: I've renamed the integer variable from 'decimal' to 'value', since there's nothing specifically decimal about it; it's just an integer. It's actually represented as binary internally.)

Converting 0x1 to 1 in java

1 Answers1