如何确定字符串是否等于Java中的数字范围？

Question

I receive input from the user that can be anything ranging from "0", "1", "2"... "F", "?", etc., and store this in a String.

How can I determine if what is stored in the string is a value from 1 to 8, without using 8 if statements?

It would look something like:

String[] inputArray = new String[3];
if (inputArray[2] == "[1 through 8]")
{
...
}

Answer 1

1. You could try with regex like

    inputArray[2].matches("[0-9A-F]") 

2. You could also use something like

    inputArray[2].length()==1 && "0123456789ABCDEF".condains(inputArray[2]) 

3. Or read first character via char ch = inputArray[2].charAt(0) (also make sure that inputArray[2] contains only one character) and see if it is in specified range 0-9 or AF like

    ('0'<=ch && ch<='9') || ('A'<=ch && ch<='F') 

Answer 2

As @user2864740 already suggested, using regular expressions would be the best solution.

http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html

Here you have the Java API for Regex in particular Pattern

Pattern p = Pattern.compile("a*b");
 Matcher m = p.matcher("aaaaab");
 boolean b = m.matches();

This example shows how Patterns should be used.