So every variation I've coded keeps coming back with 0 or 1 regardless of what I input. Excuse the length/inefficiency, just trying to make it work.
v1 - if/else tests
System.out.println("Enter a hexadecimal String to convert to decimal (base_10)");
while(true)
{
System.out.print("Hexadecimal >> ");
String hex = scan.nextLine();
String hexArray[] = hex.split("");
//int hexNum[] = new int[hexArray.length];
//System.out.println(Arrays.toString(hexArray)); //test
int sum = 0;
int exp = 0;
for (int i = hexArray.length-1; i > 0; i--)
{
if(hexArray[i].equalsIgnoreCase("A"))
sum += 10 * Math.pow(16,exp);
else if(hexArray[i].equalsIgnoreCase("B"))
sum += 11 * Math.pow(16,exp);
else if(hexArray[i].equalsIgnoreCase("C"))
sum += 12 * Math.pow(16,exp);
else if(hexArray[i].equalsIgnoreCase("D"))
sum += 13 * Math.pow(16,exp);
else if(hexArray[i].equalsIgnoreCase("E"))
sum += 14 * Math.pow(16,exp);
else if(hexArray[i].equalsIgnoreCase("F"))
sum += 15 * Math.pow(16,exp);
else
sum += (Integer.parseInt(hexArray[i]) * Math.pow(16,exp));
exp++;
}
System.out.println("\nHexadecimal: " + hex + "\t Decimal: " + sum);
}
Alternatively... v2 - switch by String
System.out.println("Enter a hexadecimal String to convert to decimal (base_10)");
while(true)
{
System.out.print("Hexadecimal >> ");
String hex = scan.nextLine();
String[] hexArray = hex.split("");
System.out.println(Arrays.toString(hexArray)); //test
int sum = 0;
int exp = 0;
for (int i = hexArray.length-1; i > 0; i--)
{
String s = hexArray[i];
switch(s)
{
case "A": case "a":
sum += (10 * Math.pow(16,exp));
break;
case "B": case "b":
sum += (11 * Math.pow(16,exp));
break;
case "C": case "c":
sum += (12 * Math.pow(16,exp));
break;
case "D": case "d":
sum += (13 * Math.pow(16,exp));
break;
case "E": case "e":
sum += (14 * Math.pow(16,exp));
break;
case "F": case "f":
System.out.println("hi");
sum += (15 * Math.pow(16,exp));
break;
default: //i.e. NUMBERS
sum += ((Integer.parseInt(hexArray[i]) * Math.pow(16,exp)));
}
exp++;
}
System.out.println("\nHexadecimal: " + hex + "\t Decimal: " + sum);
System.out.println("\n");
}
v3 - switch with char-literals
System.out.println("Enter a hexadecimal String to convert to decimal (base_10)");
while(true)
{
System.out.print("Hexadecimal >> ");
String hex = scan.nextLine();
String[] hexArray = hex.split("");
System.out.println(Arrays.toString(hexArray)); //test
int sum = 0;
int exp = 0;
for (int i = hexArray.length-1; i > 0; i--)
{
char c = hexArray[i].charAt(0);
switch(c)
{
case '0':
break;
case '1':
sum += Math.pow(16,exp);
break;
case '2':
sum += 2 * Math.pow(16,exp);
break;
case '3':
sum += 3 * Math.pow(16,exp);
break;
case '4':
sum += 4 * Math.pow(16,exp);
break;
case '5':
sum += 5 * Math.pow(16,exp);
break;
case '6':
sum += 6 * Math.pow(16,exp);
break;
case '7':
sum += 7 * Math.pow(16,exp);
break;
case '8':
sum += 8 * Math.pow(16,exp);
break;
case '9':
sum += 9 * Math.pow(16,exp);
break;
case 'A':
case 'a':
sum += 10 * Math.pow(16,exp);
break;
case 'B':
case 'b':
sum += 11 * Math.pow(16,exp);
break;
case 'C':
case 'c':
sum += 12 * Math.pow(16,exp);
break;
case 'D':
case 'd':
sum += 13 * Math.pow(16,exp);
break;
case 'E':
case 'e':
sum += 14 * Math.pow(16,exp);
break;
case 'F':
case 'f':
sum += 15 * Math.pow(16,exp);
break;
default:
; //Invalid Character
}
exp++;
}
System.out.println("\nHexadecimal: " + hex + "\t Decimal: " + sum);
Multiple ways (shown above) , but initially splitting it into an array and reading backwards R->L to increment the exponent accordingly.
In all versions of your code (v1, v2, and v3), the loop condition is i > 0. This means that the loop will stop when i becomes 1, and then it will skip the first element in your hexArray (at index 0).
Simply change the loop condition to this:
for (int i = hexArray.length - 1; i >= 0; i--)