使用霍纳算法将十六进制字符串转换为十进制数

import java.util.Scanner;

public class Hex2Dec {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		System.out.print("Enter a hex number: ");
		String hex = input.nextLine();
		input.close();
		
		System.out.println("The decimal value for hex number " + hex + " is " + hexToDecimal(hex.toUpperCase()));
	}
	
	public static int hexCharToDecimal(char ch) {
		if (ch >= 'A' && ch <= 'F') {
			return 10 + ch - 'A';
		} else {
			return ch - '0';
		}
	}
	
	public static int hexToDecimal(String hex) {
		int decimalValue = 0;
		
		for(int i = 0; i < hex.length(); i++) {
			char hexChar = hex.charAt(i);
			decimalValue = decimalValue * 16 + hexCharToDecimal(hexChar);
		}
		
		return decimalValue;
	}
	
}