Programming Forums > Application Development > Java

emdiesse · May 17th, 2007, 5:48 PM

Hello. I have a need to create 81 buttons (named btn1...btn81).

Instead of typing out

JButton btn1 	= new JButton("0")
JButton btn2 	= new JButton("0")
...
JButton btn81 	= new JButton("0")

is there a way I can use a for loop to do this

(Toggle Plain Text)

for(int i=0; i<=81; i++)
{
     JButton btni 	= new JButton("0")
}

obviously this would probably not work for two reasons it would just make a button called btni 81 times probably, also i believe there would be scope issues?

How can I do this?
or do I just have to type them all out?

Thank you

andro · May 17th, 2007, 6:02 PM

Use an array of JButton.

Edit: Just read that wrong. If you _really must_ have them named btn1..btn81 instead of just accessing the correct index of the array then yes, you'll have to type them out.

emdiesse · May 17th, 2007, 6:17 PM

Ah no, thats nasty

just a huge block of buttons.
also. I just i can't add them to the frame using a for loop either.

Oh, this means I have to put some effort in.

titaniumdecoy · May 17th, 2007, 7:13 PM

Why not just use an array?

emdiesse · May 17th, 2007, 8:18 PM

I didn't know that could be done with buttons.

Also, misread andros message. I didn't see the part saying if it was a must to have them named btn1 to btn81.

I have this now

(Toggle Plain Text)

JButton[][]btn = new JButton[9][9];
		for(int r=0;r<9; r++)
		{
			for(int c=0;c<9; c++)
			{
				btn[r][c].setSize(25,25);
				btn[r][c].setText("0");

				pane.add(btn[r][c]);
			}
		}

but when I run it I just get a blank frame.

PhilBon · May 17th, 2007, 9:11 PM

What is Pane? Variable? If so What kind? Are you updating the frame? I'm not used to working with Java frames and Panels but I'm guessing you have to make sure you update the frame somehow.

andro · May 17th, 2007, 9:32 PM

For starters, you need to add:

(Toggle Plain Text)

btn[r][c] = new JButton("0");

Before you go and try to add them.

emdiesse · May 17th, 2007, 9:38 PM

Quote:

Originally Posted by andro

For starters, you need to add:

(Toggle Plain Text)

btn[r][c] = new JButton("0");

Before you go and try to add them.

Excellent!
You just solved my problem

ReggaetonKing · May 17th, 2007, 11:20 PM

Is a 2D array necessary for your JButtons? Why not just make a single JButton with a length of 81?

May 17th, 2007, 5:48 PM	#1
emdiesse Programmer Join Date: Jul 2004 Location: Hampshire Posts: 56 Rep Power: 5	for loop variables Hello. I have a need to create 81 buttons (named btn1...btn81). Instead of typing out (Toggle Plain Text) JButton btn1 = new JButton("0") JButton btn2 = new JButton("0") ... JButton btn81 = new JButton("0") JButton btn1 = new JButton("0") JButton btn2 = new JButton("0") ... JButton btn81 = new JButton("0") is there a way I can use a for loop to do this (Toggle Plain Text) for(int i=0; i<=81; i++) { JButton btni = new JButton("0") } for(int i=0; i<=81; i++) { JButton btni = new JButton("0") } obviously this would probably not work for two reasons it would just make a button called btni 81 times probably, also i believe there would be scope issues? How can I do this? or do I just have to type them all out? Thank you

May 17th, 2007, 8:18 PM	#5
emdiesse Programmer Join Date: Jul 2004 Location: Hampshire Posts: 56 Rep Power: 5	I didn't know that could be done with buttons. Also, misread andros message. I didn't see the part saying if it was a must to have them named btn1 to btn81. I have this now (Toggle Plain Text) JButton[][]btn = new JButton[9][9]; for(int r=0;r<9; r++) { for(int c=0;c<9; c++) { btn[r][c].setSize(25,25); btn[r][c].setText("0"); pane.add(btn[r][c]); } } JButton[][]btn = new JButton[9][9]; for(int r=0;r<9; r++) { for(int c=0;c<9; c++) { btn[r][c].setSize(25,25); btn[r][c].setText("0"); pane.add(btn[r][c]); } } but when I run it I just get a blank frame.

May 17th, 2007, 9:32 PM	#7
andro Professional Programmer Join Date: Oct 2005 Location: California Posts: 319 Rep Power: 4	For starters, you need to add: (Toggle Plain Text) btn[r][c] = new JButton("0"); btn[r][c] = new JButton("0"); Before you go and try to add them.

May 17th, 2007, 11:20 PM	#9
ReggaetonKing Sexy Programmer Join Date: Nov 2005 Location: New Jersey Posts: 891 Rep Power: 4	Is a 2D array necessary for your JButtons? Why not just make a single JButton with a length of 81? __________________ I would love to change the world, but they won't give me the source code!

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May 17th, 2007, 6:02 PM	#2
andro Professional Programmer Join Date: Oct 2005 Location: California Posts: 319 Rep Power: 4	Use an array of JButton. Edit: Just read that wrong. If you _really must_ have them named btn1..btn81 instead of just accessing the correct index of the array then yes, you'll have to type them out.

May 17th, 2007, 6:17 PM	#3
emdiesse Programmer Join Date: Jul 2004 Location: Hampshire Posts: 56 Rep Power: 5	Ah no, thats nasty just a huge block of buttons. also. I just i can't add them to the frame using a for loop either. Oh, this means I have to put some effort in.

May 17th, 2007, 7:13 PM	#4
titaniumdecoy Expert Programmer Join Date: Nov 2005 Posts: 931 Rep Power: 4	Why not just use an array?

May 17th, 2007, 9:11 PM	#6
PhilBon Hobbyist Programmer Join Date: Nov 2005 Posts: 172 Rep Power: 4	What is Pane? Variable? If so What kind? Are you updating the frame? I'm not used to working with Java frames and Panels but I'm guessing you have to make sure you update the frame somehow.

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Programming Forums > Application Development > Java

for loop variables