java_2_10.java

@FXML
private void evaluate() {
		
    if (nextOperation == Operation.none) {
        input.setText("");
        lastResult.setText("");
        return;
    }		
    var lastResultFloat = Float.parseFloat(lastResult.getText());	
    var inputFloat = Float.parseFloat(input.getText());
    var result = 0f;
    switch (nextOperation) {
    case ADD:
	result = lastResultFloat + inputFloat;
	break;
    case SUBTRACT:
	result = lastResultFloat - inputFloat;
	break;
    case MULTIPLY:
	result = lastResultFloat * inputFloat;
	break;
    case DIVIDE:
	if (inputFloat == 0) {
      	    lastResult.setText("Error");
    input.setText("");
	    nextOperation = Operation.NONE;
	    return;
       }
	 result = lastResultFloat / inputFloat;
	 break;     
    default:
	return;
    }
    input.setText("");
    lastResult.setText(String.valueOf(result));		
    nextOperation = Operation.none;
}