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Is it possible to place components randomly without container in Swing window builder?

The only way, as far as I know, to put a JButton or a JLabel is via creating the GUI structure through Containers and placing those components on it.
Are there other methods to add components randomly into the frame and resize accordingly ,as can be done in Visual C# for example? What is the method to do it?

Yes.
You could use a null Layout and then place components using setBounds().
For example:
JPanel panel = new JPanel(null);
for (int i = 0; i < 4; i++) {
JButton b = new JButton("JButton-"+i);
b.setBounds(50+i*10, 50+i*10, 100, 100);
panel.add(b);
}
If you want random placing, you could random the first 2 (x,y) values.
You will need to provide on your own valid values to be placed inside the parent container.

Using a function to create multiple components and change line automatically [Java]

So i lost some hours already with this and i can't seem to find a solution.
Basically i have a Jframe and inside, i have a Scrollpane and a panel
I have 1 Jlabel, 1 JTextField and 1 JButton inside that panel in a single line.
The JButton can add a new JLabel, a new JTextField and a new JButton, but i can't get them to be positioned in the next line.
I have been messing around with the layouts, but none of them fits my needs, and unfortunaly i never understand or learned how the GUI of java Works.
How's the best way to just keep adding those componentes (Jlabel, Jtextfields and Jbuttons) on a next line for every click i made?
This is my code:
private void BtnaddvariableActionPerformed(java.awt.event.ActionEvent evt) {
JLabel Lblvariablextra = new JLabel("Testing");
PanelVariable.add(Lblvariablextra);
ScrollPaneVariable.setViewportView(PanelVariable);
}
The code only contains an exemple of the label tough.

Create a main panel that is added to the scroll pane when the GUI is created:
Box main = Box.createVerticalBox();
scrollPane.setViewportView( main );
Then in the ActionListener you create a child panel contain the 3 components every time the button is pressed:
JPanel child = new JPanel();
child.add( new JLabel("I'm a label") );
child.add( new JTextField(10) );
child.add( new JButton("Click Me") );
main.add(child);
Read the section from the Swing tutorial on Layout Manager to understand how layout management works.

Java swing GUI creation

I'm developing a Java GUI and I need:
A label in first row(only one label).
Starting 2nd row need to add say 100 buttons which extends to multiple lines(width shouldn't go beyond the visible screen)
In a new line one more Label
From next line say 100 buttons which extends to multiple lines(width shouldn't go beyond the visible screen)...
[OPTIONAL] If the components exceeds JFrame height then need a scroll facility to the main window (only vertical)
I have a strange results with flow layout, sometimes it stick to visible width, sometimes it sets even 500 buttons in a single row.
I have tried every layout and also multipanes. Still no luck.
Please guide.. just need an idea, No need of code
Updated with code: Sorry guys, that was my first question to stackoverflow
Thanks for prompt response
Infact i tried many, here is a simple one.
setLayout(new FlowLayout());
setTitle("JAVA GUI");
setSize(500,500);
setVisible(true);
add(new JLabel("row 1"));
JPanel panel1 = new JPanel(new FlowLayout());
for(int i=0;i<200;i++){
panel1.add(new JButton("b"+i));
}
add(panel1);
Here the panel1 is appearing in a sigle row which goes beyond the visible part of the screen.
I think this can be solved by setting maximumsize to Jframe, but no idea how to set its size to FULL SCREEN.

You can try MigLayout.
http://www.miglayout.com/
Also this question is not really a question for stack overflow. A good way to ask your question would be to post your code and tell us what is wrong with it and what it is supposed to do.

While this is not the norm for 'good' stackOverflow questions, I don't have any problem with it myself. Some people cannot deal with anything except code. I would suggest that, if you're going to post code, that you take the trouble to post code that will compile, run, and demonstrate your situation. It really helps those of us out here understand what you're seeing and what you're trying to do.
You talk about "rows"; be aware that rows and columns are terms used with things like GridLayout and GridBagLayout, but I don't think they're appropriate for what you describe.
In your description, you don't say what you want scrolled. It would appear you want the entirety of the UI scrolled, I'll assume that for now.
I would try a JPanel with BoxLayout, oriented vertically, for the overall main UI. You will put some things into that:
The first JPanel.
Another JPanel, set with FlowLayout, holding the first bunch of buttons.
Another JPanel with the next JLabel
And a fourth JPanel, set with FlowLayout, holding the second bunch of buttons.
Now, I would put the top-level panel into a JScrollPane, and then put that into the CENTER section of a Frame (with its default BorderLayout), and see what happens. To tell the truth, I'm not sure, but these are the things I would start with.
I cannot tell, without running code, why you get odd behavior sometimes.

As said in a previous comment, using a ContentPane is the way to go. Here is a working example of what you want:
public class Test {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setTitle("JAVA GUI");
JPanel panel1 = new JPanel();
panel1.setLayout(new BoxLayout(panel1, BoxLayout.Y_AXIS));
int nbLines = 10;
for (int i = 0; i < nbLines; i++) {
JPanel linePanel = new JPanel(new FlowLayout());
linePanel.add(new JLabel("row " + i));
for(int j = 0; j < 50; j++) {
linePanel.add(new JButton("b" + j));
}
panel1.add(linePanel);
}
frame.setContentPane(panel1);
//frame.setSize(500, 500);
frame.setExtendedState(frame.getExtendedState() | JFrame.MAXIMIZED_BOTH);
frame.pack();
frame.setVisible(true);
}
}
And here is what I get:
If you want to have left-aligned buttons you can use:
JPanel linePanel = new JPanel(new FlowLayout(FlowLayout.LEFT));

mixing gridlayout and borderlayout

I was tired but before quitting just stuck in the nearly-last 3 lines in the code snippet below to make a "refresh" button on my tictactoe panel, hoping to get away with it but expecting errors, since it mixes layout managers on a single container.
But it WORKED.
ButtonPanel.setLayout(new GridLayout(3, 3));
guiFrame.add(ButtonPanel);
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
button[i][j] = addButton(ButtonPanel, i, j);
}
}
JButton refreshbutton = new JButton("Refresh");
guiFrame.add(refreshbutton, BorderLayout.SOUTH); // ... border layout worked. Hm.
refreshbutton.addActionListener(this);
guiFrame.setVisible(true); }
Should I be surprised? (Keep in mind my newbieness.)
(BOY, did I learn/stumble onto a buncha stuff in writing this silly game's program!!!--for instance, using setActionCommand to "label" each button internally [as 11,12,13,21,...33] so the ONE actionPerformed method could use getActionCommand to correctly label [with X or O] whatever button was pushed by whoever's turn it was.)

guiFrame.add(refreshbutton, BorderLayout.SOUTH); // ... border layout worked. Hm.
Just because you used BorderLayout.SOUTH does not make a panel a BorderLayout. Your code worked because the default layout manager for the content pane of a JFrame (JDialog) is a BorderLayout. So you are just taking advantage of the default layout.
since it mixes layout managers on a single container.
Yes, this is a common practice. In fact it is almost impossible to create a reasonably complex GUI if you don't use different layout managers on different panels that you add to a GUI.

Adding JPanels through a loop

Made it work! Thank you guys! The code follows. I used BoxLayout since I thought it'd be ideal for stacking questions one on top of the other, but now I got issues with the layout... When I stack several questions the question panels start overlapping. Any thoughts?
panels1 = new MultipleChoice[5];
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
for(int i=0; i<4; i++){
panels1[i]= new MultipleChoice();
panels1[i].setAlignmentX(CENTER_ALIGNMENT);
add(panels1[i]);
}
setVisible(true);
I'm working on designing an Online Test applet. A test has multiple choice and true/false questions. To set up a test I created two JPanel classes, one for the multiple choice question and one for the true/false questions. So when a test is created I'll just dynamically add these panels to a JPanel container according to the non-fixed number of questions.
First, how can I dynamically add new panels to a panel? I thought about declaring an array of the JPanel type. I created and then add objects of this panel class using a for loop:
MultitipleChoicePanel[] PanelArray;
for (...){
PanelArray[i] = new MultipleChoicePanel();
containerpanel.add(PanelArray[i]);
}
I don't know if this is technically possible. This is my first time using Swing, and I tried doing this but obviously it didn't work. Does anyone have an idea how correctly dynamically add these panels?
Second, which of the layout managers is best suited for the container panel in order to fit every new panel added right under the previous one? I thought about dynamically setting up a GridLayout of one column and add rows as I add panels. But I've been really struggling modifying swings dynamically.
Any suggestions?
Thank you so much for your help!

JPanel default layout is FlowLayout and add each component by default to the right so it would fit your problem.
You also may interested in swingx they have HorizontalLayout.
Example:
//in some place
JPanel myBigPanel = new JPanel();
myBigPanel.setLayout(new HorizontalLayout()); // swingx api
List<MultitipleChoicePanel> panelList = new ArrayList<>();
// panelList.add(new MultipleChoicePanel()).. .n times
for(MultipleChoicePanel mp : panelList){
myBigPanel.add(mp);
}
myBigPanel.revalidate(); // revalidate should call repaint but who knows
myBigPanel.repaint();
How to use various Layout Managers

how correctly dynamically add these panels?
After adding components to a visible GUI you need to do:
panel.add(...);
panel.revalidate();
panel.repaint();

"and then add objects of this panel class using a for loop:.....I dont know if its technically possible"
As far as an array of panels, I would do it with an arraylist and do it similarly to how you did it.
import java.util.ArrayList;
ArrayList<MultipleChoicePanel> array = new ArrayList<MultipleChoicePanel>();
for(...){
array.add(new MultipleChoicePanel());
containerPanel.add(array.get(i));
}

import java.awt.*;
import javax.swing.*;
public class JavaSwing extends JApplet {
public void init(){
Container content = getContentPane();
JScrollPane pane= new JScrollPane();
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel,BoxLayout.Y_AXIS));
panel.add(addPanel("title121"));
panel.add(addPanel("title112"));
panel.add(addPanel("title12"));
panel.add(addPanel("title11"));
pane.getViewport().add(panel);
content.add(pane);
}
public static JPanel addPanel(String title){
JPanel panel = new JPanel();
panel.add(new JButton(title));
return panel;
}
}