quesion - how to display an array in an applet?

[EBBOOO]

hi all,

i'm working in a project now. i know how to declare arrays but i never use them in an applet.

so my question is how can i view two dimensions arrays in applet??

also, how can i get data from a user and save it in the array??

[travishein]

this sounds like a JTable

[Norm]

Use a text field to get data from a user.

[EBBOOO]

thanks for your replies
the number of students will be given by the user
i now know how can i add textfields as the number entered by the user, but the question is, how can i store the entered names (by user) in an array??

[Norm]

1) get the data out of the text field into a String. Read the API doc for the text field class for which method to use
2) put a reference in the array to that String: array[ix] = string;

[EBBOOO]

i am sorry, i am a beginner in Java, and i did not really understand all what you posted

let me give an idea of what i am doing in my program, the program is to ask the user he enter a number of students. then the same number of textfields must be displayed. the user has to enter students names, and grades for 6 subjects.
my question is if i want to display all students names and grades in a table, find the averages of each student and each subject? how can i store the entered grade of student name in the array. should i use only one textfield for students names and one for grades? if yes, how can get the data from the textfield and store it in the array

[Norm]

JTable would give a nicer but I'm not sure if a beginner would be up to it.
Otherwise use a layout manager like GridLayout to build simple table of text fields.
Are you going to get the names and grades one at a time from the user and then display them all after they have been processed? Does each student have grades for 6 courses?
Then the table would have 7 columns, one for name and 6 for grades. Plus maybe another column for the averages.

how can i store the entered grade of student name in the array.

1) where do you get the grade? Input to a text field by user?
Read text field API doc for methods to get data from text field.
Once grade is in a String, convert it to number by method of Integer or Double class.
2) Store grade in an array?
Make an array of proper type: int or float. Decide which element to put the grade in and assign that element the grade: array[ix] = grade;

[EBBOOO]

Many thanks for your help
but How many text fields i have to define?

[Norm]

If there are 6 text flelds on a row and there are 6 rows, that would require 36.

[j2me64]

hope the following code give you some ideas how to implement your requirements

		import java.applet.Applet;
import java.awt.BorderLayout;

import javax.swing.JPanel;
import javax.swing.JTextArea;

public class Test extends Applet {
	
	private static final long serialVersionUID = 1L;

	public void init() {
		JTextArea area = new JTextArea();
		area.setEditable(false);
		
		
		int[][] arr = { { 0, 1 }, { 1, 1 }, { 2, 1 } };
		String str = "";

		for (int r = 0; r < arr.length; r++) {
			str += "Array[" + r + "][1] = ";
			for (int c = 0; c < arr[r].length; c++) {
				str += arr[r][c] + " ";
			}
			str += "\n";
			area.append(str);
			str = "";
		}
		add(area, BorderLayout.CENTER);
	}
}

modify the code according to your requirements.

[EBBOOO]

many thanks to all of you for your help

i just knew that textfields can be declared in an array :)

but there is one problem i do not know what how to solve it, which is where should i write the loops, should i create another public void main () and write it there?

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

public class students_grades extends Applet implements ActionListener {
Label title = new Label("<{This program calculate students grades in 6 subjects}>");
Label number_of_students = new Label("<{Inter the number of the students}>");
TextField number_of_students_ = new TextField(5);
Button View_Table = new Button ("View Table");


public void init( ) {
//setLayout();
add (title);
add (number_of_students);
add (number_of_students_);
add (View_Table);
number_of_students_.addActionListener(this);
View_Table.addActionListener(this);

}
public void actionPerformed(ActionEvent event) {

// to get the number of students entered by user
// String titles [8] = [No. , Student Name, Math, Comp, Salam, Arab, MGT, ORG];
String number_of_students_text = number_of_students_.getText();
int number_of_students_int = Integer.parseInt(number_of_students_text);

// define two arrays of textfield
TextField txtname []= new TextField [number_of_students_int];
TextField txtgrade [][] = new TextField [number_of_students_int][6];

// define two arrays ===> one for student names, and the other one for students grade
String students_names [] = new String [number_of_students_int];
float students_grades [][] = new float [number_of_students_int][6];

// add name text fields
for (int i=0; i<number_of_students_int; i++)
{
add (txtname[i]);
}
// add grade text fields in 2D array
for (int i=0; i<number_of_students_int ;i++)
{
for (int j=0; j<6 ; j++)
{
add (txtgrade[i][j]);
}
}

// get text from text fields and save it in the array
for (int i=0; i<number_of_students_int; i++)
{
students_names [i] = txtname[i].getText();
}

for (int i=0; i<number_of_students_int ;i++)
{
for (int j=0; j<6 ; j++)
{
String Container = txtgrade[i][j].getText();
int intContainer = Integer.parseInt(Container);
students_grades[i][j] = intContainer;
}
}


} // action performed
} // class

[JosAH]

many thanks to all of you for your help

i just knew that textfields can be declared in an array :)

but there is one problem i do not know what how to solve it, which is where should i write the loops, should i create another public void main () and write it there?

(J)Applets don't have a main( ... ) method (you could've read that in your books); they have an init() method where it all starts.

kind regards,

Jos

[EBBOOO]

thanks Jos
I've heard this before but i don't know what it's really mean, cause I'm just a beginner

so, what exactly should i add? or change?

[curmudgeon]

My interpretation of what Jos is mainly saying is that you should RTFM. The information on JApplets can be obtained here.

Getting Started With Applets (The Java™ Tutorials > Deployment > Applets)

Have fun.

[Norm]

For now forget about running the code in an applet. Just work on building the GUI in a JPanel and put that panel in a JFrame. Applet extends Panel, so most of your techniques should work there.