How to convert string representing number i any format to integer

Question

I have a string which I want to convert to Integer, I know that this can be achieved using Integer.parseInt(number) Or by using Integer.parseInt(number, base) for a particular base.
I can use above function with a if else condition to check the base of number represented by string.
Example:

int intValue;
if(string.startsWith("0x"))
    intValue = Integer.parseInt(string.substring(2), 16)
//handle other cases
else
    intValue - Integer.parseInt(string)  //base 10

I was wondering if there is there any inbuilt function that does this job of converting string representing number in any base to corresponding integer?

Answer 1

Integer.decode(String nm) is designed exactly for your needs. From docs:

The sequence of characters following an optional sign and/or radix specifier ("0x", "0X", "#", or leading zero) is parsed as by the Integer.parseInt method with the indicated radix (10, 16, or 8).

Here is fragment of Integer source code responsible for radix distinction:

if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) {
    index += 2;
    radix = 16;
} else if (nm.startsWith("#", index)) {
    index ++;
    radix = 16;
} else if (nm.startsWith("0", index) && nm.length() > 1 + index) {
    index ++;
    radix = 8;
}