/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
	        char[] keyArray =  {'*'};
        char[] valueArray = {'*'};
        String myString = "abcxyz";
        char[] myStringArray = myString.toCharArray();
 
        for(int x = 0; x<myString.length(); x++)
        {
            for(int i = 0; i<keyArray.length; i++)
            {
                if(myStringArray[x] == keyArray[i])
                {
                    //System.out.println(valueArray[i]); would give the output "zyxcba" as expected 
                    myStringArray[x] = valueArray[i]; // this will only change the characters in the first half of keyArray 
                }
            }
        }
 
        System.out.println(myStringArray);}
}

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

aGVsbG8=

hello