if (buttonText.equals("C")) {
            if (dataToCalculate == null || dataToCalculate.isEmpty()) {
                Toast.makeText(this, "No values to delete", Toast.LENGTH_SHORT).show();
                resultTv.setText("0");

            } else {

                if (dataToCalculate.length() > 1) {
                    dataToCalculate = dataToCalculate.substring(0, dataToCalculate.length() - 1);
                } else {
                    dataToCalculate = ""; // Clear if only one character remains
                    resultTv.setText("0");

                }
                solutionTv.setText(dataToCalculate);


                if (!dataToCalculate.isEmpty()) {
                    String finalResult = getResult(dataToCalculate);
                    if (finalResult.isEmpty() || finalResult.equals("Err")) {
                        resultTv.setText("0");
                    } else {
                        resultTv.setText(finalResult);
                    }
                } else {
                    resultTv.setText("0");
                }

               return;

need help with the above Java code, where I need to fix the issue that the code is taking “C” as input when no values are present.