title: javafx make a grid of buttons
body: <p>I want to make a grid with a specific amount of buttons.
  I know how many buttons there are need to be because I get the number of rows and columns. </p>
  
  <p>I could do a loop, but I don't know how you can place buttons next to eachother and underneath.<br>
   Secondly, the buttons need a Text and an Id, text is no problem, but how do you give them an id?<br>
  And at last, and probably most difficult, it can occur that there are a lot of rows, so that a scrollbar should be available.</p>
  
  <p>At the end it should look something like this: </p>
  
  <p><img src="https://i.stack.imgur.com/0Ljq4.png" alt="enter image description here"></p>