Java - replace() method using values from arrays is changing the array values?

Question

I\'m doing something like

public static String[] list = {\"a\",\"b\",\"c\",\"d\",}  //It gives me a NullPointeException if I didn\'t use static
public String en         


        

Answer 1

I suspect your question is "why is chaining .replace acting oddly" and the array is not changing. You can prove that replace does not change the array quite easily:

    System.out.println(Arrays.toString(list));
    encrypt("abc");
    System.out.println(Arrays.toString(list));

So what is going on with your code? Each time you replace a letter you end up with a new string, that again you replace letters on. I don't have your full source code so I'll show with a real simple version:

a = a.replace("a", "b");
a = a.replace("b", "c");
a = a.replace("c", "d");

For "abc" is.... 'ffffd'.

The answer to this is to look at each letter at a time and change it. Loop through the string and create a new one.