Java - Convert hex to decimal - make a string = the correct number

Question

ERROR WAS DUE TO A MISTAKE WHICH WAS OVERLOOKED

I recently created a Java program that converts an rgb value to hexadecimal. Now I am trying to make a program that will do the opposite. I already figured out the algorithm I am going to use, I just need to convert the characters A - F to the values 10 - 15. Seems simple right? This is where I hit my problem.

Here is the code I have so far. A string is fed into nums() which then checks it against the array abc. Once a match is found it takes takes the string a and converts it to an integer, then takes i and will add 10 in order to get the right number.

class TextToNum {
  String[] abc = { "A", "B", "C", "D", "E", "F" };
  public int nums(String a) {
    for(int i = 0; i < abc.length; i++) {
      if (a == abc[i]) {
        a = Integer.parseInt(a.trim());
        a = i + 10;
      }
    }
    return a;
  }
}

The errors I get are:

gbConv.java:52: incompatible types
found   : int
required: java.lang.String
                a = Integer.parseInt(a.trim());
                                    ^
rgbConv.java:53: incompatible types
found   : int
required: java.lang.String
                a = i + 10;
                      ^
rgbConv.java:56: incompatible types
found   : java.lang.String
required: int
        return a;
               ^

It is obvious that something is wrong with the Integer.parseInt() but I am not sure how to fix it. I have been looking on the web and I can't find anything. Any suggestions / tutorials would be a great help.

Solution 1

To convert a hex string to an int, you could simply use Integer.parseInt(str, 16).

Solution 2

Why dont you try which is already available.

  Color.decode("hex string");

Solution 3

Integer.parseInt(String str) works only if str contains integer. Like if you have string as str="12345" Integer.parseInt(str) results 12345 as integer.

But in your case mentioned you are passing either one of "A", "B", "C", "D", "E", "F".