Can someone halp me? (JAVA)

Question

When i write this code in eclipse it work perfectly, but when i tried to write it in sololearner it doesn't. Can someone halp me, and tell me where is a mistake?

This is code(it's java):

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;

public class MathFX extends Application {

TextField txtnum1, txtnum2;

Button btnadd, btnsub, btndiv, btnmul, btnclear;

Label lblanswer;

@Override

public void start(Stage primaryStage) {

//pravim kontrole

txtnum1=new TextField();

txtnum2=new TextField();

btnadd=new Button("+");

btnsub=new Button("-");

btnmul=new Button("x");

btndiv=new Button("/");

btnclear=new Button("Clear");

lblanswer=new Label("?");

//center text in label

lblanswer.setAlignment(Pos.CENTER);

//apply ccs-like style to label (yes, you can)

lblanswer.setStyle("-fx-border-color: #000; -fx-padding: 5px;");

//make container for app

GridPane root = new GridPane();

//put container in middle of scene

root.setAlignment(Pos.CENTER);

//setspacing between controls in grid

root.setHgap(10);

root.setVgap(10);

//add to grid, cell by cell

root.add(btnadd,0,0);

root.add(btnsub,1,0);

root.add(btnmul,0,1);

root.add(btndiv,1,1);

root.add(txtnum1, 0,2);

root.add(txtnum2,1,2);

//last 2 rows span across 2 columns

//col, rol, colspan, rowspan

root.add(lblanswer,0,3,2,1);

root.add(btnclear,0,4,2,1);

//set widths of all controls in separate m

Answer 1

Jel se profesionalno bavis programiranjem?

Answer 2

JavaFX is not supported at the playground, nor is any other gui framework.

Answer 3

When you say (work in others, not in sololearn), I can easily say,
The Sololearn Code Playground sucks. To run complex code you shouldn't use Code Playground

Answer 4

some codes are not supported by sololearn playground

Answer 5

Studiram programiranje na matematickom fakultetu, a nadam se da cu se kasnije baviti profesionalno

Answer 6

I am studing programing on University of Belgrade, and i hope i will be professional after that

Answer 7

Are you professional?

Answer 8

Ja krenuo pre neki dan na ITakademiju, jel mogu ovde da se pisu PM?

Answer 9

Private mesagge

Answer 10

Gde bih mogao da ti pisem, ako mi zatreba neka pomoc? Naravno ako moze tako

Answer 11

Instagram?

Answer 12

Isto