Q#7 Parikosh's test

[jing zhao]

The answer is 2.
What's the "North" and "South" use??
add(new Button("Three"), "North");
add(new Button("Four"), "South");
Thanks.
Q#7 What best describes the appearance of an application with the following code?
import java.awt.*;
public class FlowAp extends Frame{
public static void main(String argv[]){
FlowAp fa=new FlowAp();
fa.setSize(400,300);
fa.setVisible(true);
}
FlowAp(){
setLayout(new GridLayout());
add(new Panel());
add(new Button("One"));
add(new Button("Two"));
add(new Button("Three"), "North");
add(new Button("Four"), "South");
}
}
1) A Frame with buttons marked One to Four placed on a Panel
2) A panel and buttons marked One to four running from the left to right
3) A Frame with one large button marked Four in the Centre
4) An Error at run time indicating you have not set a LayoutManager properly
5) An Error at compile time indicating add is called with invalid parameters.

[shashank hiwarkar1]

Hi Jing,

Here u r using layout as GridLayout(),
Gridlayout has constructor as "gridlayout(x,y)"
here x=no. of rows
y = no. of columns
but if you are not passing any arguments to the constructor, it will treat as (1,n)
ie number of components added will be arranged in one row from left to right

Shashank

[natarajan meghanathan]

I agree.
The answer should be 2.

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Sun Certified Programmer for Java 2 Platform
***********************************************

[Manfred Leonhardt]

Hi Jing,
The 'trick' here is that the Container class provides the add methods that are used by the AWT containers. It is up to each layout if it accepts and uses all the given parameters. In the case you have given, the GridLayout doesn't accept any constraints therefore it chooses to ignore the second parameter in the add() method. It is used to confuse you!
By default a GridLayout creates a single row with many columns. Therefore your result will be 2.
Regards,
Manfred.

[jing zhao]

I run the program, the 2 is right. In the add() method, it chooses to ignore the second paramter, that confused me.
Thanks all your help.

Originally posted by Manfred Leonhardt:
Hi Jing,
It chooses to ignore the second parameter in the add() method
The 'trick' here is that the Container class provides the add methods that are used by the AWT containers. It is up to each layout if it accepts and uses all the given parameters. In the case you have given, the GridLayout doesn't accept any constraints therefore it chooses to ignore the second parameter in the add() method. It is used to confuse you!
By default a GridLayout creates a single row with many columns. Therefore your result will be 2.
Regards,
Manfred.