Removing Commas and Square Brackets from Stack or String in Java Android Studio

I'm working on some anroid studio projects. I have a problem.

I have a stack named result_stack. -> result_stack = [K, T, E, J, O, S, O, G, O, J]

I tried to convert this stack in to string -> String final_result = String.valueOf(result_stack);

Now when I try to print final_result -> System.out.println(final_result); -> it prints [K, T, E, J, O, S, O, G, O, J]

But I want to get rid of all commas, square brackets and spaces. I mean, I want to print it like this "KTEJOSOGOJ" and then I'll set this as a textview.

I tried this but nothing has changed:

final_result.replaceAll(",", "");
System.out.println(final_result);

I still get [K, T, E, J, O, S, O, G, O, J] as output. Please help me with this.

The reason you're still seeing the old value is because Strings are immutable (once they've been created, they don't change.)

The solution is to set your final_result variable to the result of your replaceAll method call. Strange, I know.

Like this: final_result = final_result.replaceAll(",", "");

p.s. You'll need to replace the spaces and the brackets too, but you'll figure that out

Don't call String.valueOf(result_stack) or result_stack.toString(), and try to "fix" the result. Build the string correctly instead.

Stack<String> result_stack = new Stack<>();
result_stack.addAll(Arrays.asList("K", "T", "E", "J", "O", "S", "O", "G", "O", "J"));

// The wrong way, don't do this
String final_result1 = String.valueOf(result_stack);
System.out.println(final_result1);

// The correct way (Java 8+)
String final_result2 = result_stack.stream().collect(Collectors.joining());
System.out.println(final_result2);

// The correct way (Java 1.5+)
StringBuilder buf = new StringBuilder();
for (String value : result_stack)
	buf.append(value);
String final_result3 = buf.toString();
System.out.println(final_result3);

Output

[K, T, E, J, O, S, O, G, O, J]
KTEJOSOGOJ
KTEJOSOGOJ

Use a regular expression to remove all symbols but letters

String final_result = String.valueOf(result_stack).replaceAll("[^a-zA-Z]", "");

I did it with an array instead of a stack, but if you get the square brackets and commas when you convert the stack to a String, the same idea applies, you just need some calls to replace():

import java.util.*;
public class MyClass {
    public static void main(String args[]) {
      String[] array = {"K", "T", "E", "J", "O", "S", "O", "G", "O", "J"};
      System.out.println(Arrays.toString(array).replace(",","").replace("[","").replace("]","").replace(" ",""));
    }
}

This prints the following: KTEJOSOGOJ

Then again, you can achieve the same thing with a call to substring()instead of so many calls to replace(). Remember that strings are immutable in Java so you need to assign the results of methods you call on an object of type String unless you chain them as input for another method like I did.

String HomeName = "[K, T, E, J, O, S, O, G, O, J]";
String Replace = HomeName.replaceAll("[^a-zA-Z0-9\\\\s+]","");
UserName.setText(Replace);

Output

KTEJOSOGOJ