trying to create an array with multiple values per instance

[aconti]

Hello,

wen trying to create the below

String abc[] = {
new String (Boston, 7);

I get Boston cannot be resolved to a variable

I need to give abc[0] with both Boston and number 7 values

[Jonah Bron]

That bit of code there is not valid Java. What you want is a two-dimensional array.

Object[][] foo = new Object[] {
    new Object[] {"Boston", new Integer(7)}
};

With that code, access the values like this:

System.out.println((String) foo[0][0]); // ouputs Boston
System.out.println((Integer) foo[0][1]); // ouputs 7

Notice that, because you have to type the array as Object (since you want to store Integers and Strings), you must cast them back to their original type.

[Jonah Bron]

After further consideration, a Map might be better for this. What is the integer for? Is that an ID, or some attribute of Boston?

[aconti]

the number 7 is an attribute for Boston which needs to be stored also at Instance 0

I was sure that this was done quite simply by something like this:

String abc[] = {
new String (Boston, 7);

is the above completely wrong or maybe I have some small syntax error ?

[Iron Lion]

You'd be better off creating a class to group your data together.

class Foo {
    String str;
    int num;
    public Foo(String str, int num) {
        this.str = str;
        this.num = num;
    }
}
...
Foo[] fooArray = new Foo[2];
fooArray[0] = new Foo("Boston", 7);
fooArray[1] = new Foo("London", -34);

[aconti]

unfortunately still I am not getting any output from the below...


public class Foo {

public static void main(String[] args) {
}
String str;
int num;
public Foo(String str, int num) {
this.str = str;
this.num = num;
}



Foo[] fooArray = new Foo[2];{

fooArray[0] = new Foo("Boston", 7);

fooArray[1] = new Foo("London", -34);



System.out.println(fooArray[1]);

}

}

[Iron Lion]

First and foremost, the above generates no output because your main() method contains no code.

Secondly, printing fooArray[1] will not produce the output you're expecting because Foo doesn't override toString(). Instead, it'll produce a string of what appears to be gibberish.

To be able to do anything meaningful with a Foo's fields, you'll need to do one of two things:

• Refer to the fields directly (usually considered bad practice). Example:
  

  System.out.println(fooArray[1].str);

  Note that you'll only be able to do this if the class you're accessing the code from has access to the fields.
• Create getter/setter methods for each field (recommended). After creating such a method, you'd be able to do something like:
  

  System.out.println(fooArray[1].getStringValue());

[aconti]

Create getter/setter methods for each field (recommended).

Were can I get help/examples of how to set these please ?

[Junky]

unfortunately still I am not getting any output from the below...

Another classic example of people blindly copying code without understanding it and then whine when it doesn't do what they want.

[Jonah Bron]

Create getter/setter methods for each field (recommended).

Were can I get help/examples of how to set these please ?

A setter or getter is just a method that either sets a class property to a value, or returns it. Here's a setter:

public void setString(String value) {
    this.str = value;
}

Here's a getter:

public string getString() {
    return this.str;
}

[JosAH]

Another classic example of people blindly copying code without understanding it and then whine when it doesn't do what they want.

What's wrong with that? Isn't that how programming is done nowadays? Personally I'm very advanced: when I copy and paste some stuff from teh net and it doesn't work I throw myself to the floor, start kicking around and scream on the top of my lungs until it's fixed.

kindest regards,

Jos

[Junky]

I'd pay money to see that!

[JosAH]

I'd pay money to see that!

Feeding times at 1:00pm; please don't stick your hands through the fence.

kind regards,

Jos

[Tolls]

What's wrong with that? Isn't that how programming is done nowadays? Personally I'm very advanced: when I copy and paste some stuff from teh net and it doesn't work I throw myself to the floor, start kicking around and scream on the top of my lungs until it's fixed.

kindest regards,

Jos

You're one of my sons aren't you? Why aren't you in school?

[JosAH]

You're one of my sons aren't you? Why aren't you in school?

Dad! Dad! I had to stay out of school because you forgot to pay me my allowance! Gimme my loot!

kindest regards,

Jos ;-)