Did anybody please explain me wat is the problem here...
it is showing a null pointer exception...
class array
{
String var;
public static void main(String args[])
{
array obj[];
obj = new array[1];
obj[0].var="A";
System.out.println(obj[0].var);
}
}
The array is initialized with null's. So you need to add a new instance of array in your class first before accessing attributes from it:obj = new array[1];
obj[0] = new array();
// ...
array is not a very suitable name for your class since it does not hold an array or list of some kind. It only holds one String, so StringHolder would be a better name (note that class names always start with a capital!)
> Thanx prometheuzz .....
You're welcome Reon.
Note that you can create and initialize your array in one step:array[] obj = {new array(), new array(), new array()};
which creates an array with size 3 containing three array-objects.
Good luck.
Then how can we do this when there is equal to or more than 3 arrays...
its also showing null pointer exception....
class array
{
String id;
String name;
int age;
/*public void displaydetails()
{
System.out.println("Your id is : " + id);
System.out.println("Your name is : " + name);
System.out.println("Your age is : " + age);
}*/
public static void main(String args[])
{
//array[] aobj={new array(), new array(), new array()};
array aobj[];
aobj = new array[3];
for(int i=0;i!=3;i++)
{
aobj[0].id="AO12";
aobj[0].name="Name";
aobj[0].age=1;
aobj[1].id="AO121";
aobj[1].name="Name1";
aobj[1].age=11;
aobj[2].id="AO122";
aobj[2].name="Name2";
aobj[2].age=12;
}
for(int q=0;q!=3;q++)
{
System.out.println(aobj[q]);
}
}
}
> ...
> //array[] aobj={new array(), new array(), new array()};
> array aobj[];
> aobj = new array[3];
Uncomment that first line and comment the other two.
> for(int i=0;i!=3;i++)
> {
> aobj[0].id="AO12";
> aobj[0].name="Name";
> aobj[0].age=1;
>
> aobj[1].id="AO121";
> aobj[1].name="Name1";
> aobj[1].age=11;
>
> aobj[2].id="AO122";
> aobj[2].name="Name2";
> aobj[2].age=12;
> }
Why are you looping here? Everytinh insice the loop is executed three times, so this is what happens when you run your code:
aobj[0].id="AO12";
aobj[0].name="Name";
aobj[0].age=1;
aobj[1].id="AO121";
aobj[1].name="Name1";
aobj[1].age=11;
aobj[2].id="AO122";
aobj[2].name="Name2";
aobj[2].age=12;
aobj[0].id="AO12";
aobj[0].name="Name";
aobj[0].age=1;
aobj[1].id="AO121";
aobj[1].name="Name1";
aobj[1].age=11;
aobj[2].id="AO122";
aobj[2].name="Name2";
aobj[2].age=12;
aobj[0].id="AO12";
aobj[0].name="Name";
aobj[0].age=1;
aobj[1].id="AO121";
aobj[1].name="Name1";
aobj[1].age=11;
aobj[2].id="AO122";
aobj[2].name="Name2";
aobj[2].age=12;
Perhaps you meant to do this:
for(int i = 0; i < aobj.lentgh; i++) {
aobj[i].id = ...
aobj[i].name = ...
aobj[i].age = ...
}
> for(int q=0;q!=3;q++)
> {
> System.out.println(aobj[q]);
> }
> }
> }[/code]
And please rename your class into Person or Employee or something: it is NOT an array. In your main method you can call your variable an array:
public static void main(String args[]) {
Person[] array = new Person[3];
// ...
}
y i looped there because i just transfer that variable through there on arrays it wont repeat as u said...
dont think everything inside the for loop will give output as much time as we set...
i transferred this idea to array.. wat do u think...
class array
{
public static void main(String args[])
{
String var[];
var = new String[3];
for(int i=0;i!=3;i++)
{
var[0]=new String("HI 0");
var[1]=new String("HI 1");
var[2]=new String("HI 2");
}
for(int q=0;q!=3;q++)
{
System.out.println(var[q]);
}
}
}
did this output repeat more than one time i just mean it and i give this same idea to arrays.....
> > ...
> > Complete that line.
> > what will ?
>
> If [...] then I will give up trying to explain things to you.
The OP gave me a hard time trying to explain it to him in this forum too:
http://www.thescripts.com/forum/forum130.html
kind regards,
Jos ;-)
