How to create an Array of Object

Is this correct:
Object[] anArray = new Object[5];
Thanks.

Your code will create an array of 5 null references to class Object. After that line you could code:anArray[0] = new Integer(5);- or -
Object x = anArray[1];but if you code:anArray[3].DoSomething();and have not initialized anArray[3], you will get a NullPointerException.
Doug

Similar Messages

Creating an arrays of objects from a class

I was wondering does any one know how to create an array of objects from a class?
I am trying to create an array of objects of a class.
class name ---> Class objectArray[100] = new Class;
I cant seem to make a single class but i need to figure out how to create an array of objects.
I can make a normal class with Class object = new Class

There are four lines of code in your for-loop that actually do something:
for(index = 0; index < rooms.length; index++) {
/*1*/ assignWidth.setWidth(Double.parseDouble(in.readLine()));
/*2*/ rooms[index] = assignWidth;
/*3*/ assignLength.setWidth(Double.parseDouble(in.readLine());
/*4*/ rooms[index] = assignLength;
}1.) Sets the width of an object, that has been instantiated outside the loop.
2.) assigns that object to the current position in the array
3.) Sets the width of a second object that has been instantiated outside the loop
4.) assigns that other object to the current position in the array
btw.: I bet you meant "assignLength.setLength(Double.parseDouble(in.readLine());" in line 3 ;)
Since each position in an array can only hold one value, the first assignment (line 2) is overwritten by the second assignment (line 4)
When I said "construct a new room-object and assign it to rooms[index]" I meant something like this:
for(index = 0; index < rooms.length; index++) {
    Room aNewRoom = new Room();
    aNewRoom.setWidth(Double.parseDouble(in.readLine()));
    aNewRoom.setLength(Double.parseDouble(in.readLine());
    rooms[index] = aNewRoom;
}1.) Constructs a new Object in every iteration of the for-loop. (btw: I don't know what kind of objects you're using, so this needs most likely modification!!)
2.) set the width of the newly created object
3.) set the length of the newly created object
4.) assign the newly created object to the current position in the array
-T-
btw. this would do the same:
for(index = 0; index < rooms.length; index++) {
    rooms[index] = new Room();
    rooms[index].setWidth(Double.parseDouble(in.readLine()));
    rooms[index].setLength(Double.parseDouble(in.readLine());
}but be sure you understand it. Your teacher most likely wants you to explain it ;)

Formatted .data file, reading in and creating an array of objects from data

Hi there, I have written a text file with the following format;
List of random personal data: length 100
1 : Atg : Age 27 : Income 70000
2 : Dho : Age 57 : Income 110000
3 : Lid : Age 40 : Income 460000
4 : Wgeecnce : Age 43 : Income 370000
and so on.
These three pieces of data, Name,Age and Income were all generated randomly to be stored in an array of objects of class Person.
Now what I must do is , read in this very file and re-create the array of objects that they were initially written from.
I'm totally lost on how to go about doing this, I have only been learning java for the last month so anyone that can lend me a hand, that would be superb!
Cheers!

Looking at you other thread, you are able to create the code needed - so what's the problem?
Here's an (not the only) approach:
Create an array of the necessary length to hold the 3 variables, or, if you don't know the length of the file, create a class to contain the data. Then create an ArrayList to hold an instance of the class..
Use the Scanner class to read and parse the file contents into the appropriate variables.
Add each variable to either the array, or to an instance of the class and add that instance to the arraylist.

How to create an array using reflection.

How to create an array using reflection.
I want to achive something like this,Object o;
o = (Object)(new TestClass[10]);but by use of reflection.
To create a single object is simple:Object o;
o = Class.forName("TestClass").newInstance();But how do I create an array of objects, when the class of objects is known only by name? (Can't use Object[] because even though an Object[] array can be filled with "TestClass" elements only, it Cannot be casted to a TestClass[] array)
Anybody knows?":-)
Ragnvald Barth
Software enigneer

Found it!
the java.lang.reflect.Array class solves it!
Yes !!!

How to create transport request in object transport

How to create transport request in object transport from server to server
thanks in advance
arya

hi,
when ever u r creating any object in devlopment and saving it will ask for request.create request and release in se09.
put mail to basis people to transport ,thy will transport using STMS transaction.

How to create a LONG TEXT object in BAPI_ALM_NOTIF_CREATE

Dear experts,
Would you please give me a hand how to create a LONG TEXT object when creating a new Notification using BAPI_ALM_NOTIF_CREATE.
The snapit of my code is below. The Notification is created but without a long text.
THANK YOU!!
Data:
    lv_it_longText type STANDARD TABLE OF BAPI2080_NOTFULLTXTI,
      lv_st_longText like LINE OF lv_it_longText,
lv_st_longText-OBJTYPE = 'QME'.
lv_st_longText-TEXT_LINE = DESCRIPTIONLONG.
CALL FUNCTION 'BAPI_ALM_NOTIF_CREATE'
EXPORTING
EXTERNAL_NUMBER          =
   notif_type               = 'M1'
    notifheader              = lv_header
TASK_DETERMINATION       = ' '
SENDER                   =
ORDERID                  =
IMPORTING
   NOTIFHEADER_EXPORT       = lv_header_import
TABLES
*NOTITEM                  =   lv_it_item
NOTIFCAUS                =
NOTIFACTV                =
NOTIFTASK                =
NOTIFPARTNR              =
   LONGTEXTS                = lv_it_longText
KEY_RELATIONSHIPS        =
   RETURN                   = lv_it_return.

Hi
Make sure you have filled OBKEY.
OBJKEY must have the corresponding sort field for the values named below :-
1. QMEL - Notification header
2. QMFE - Notification item
3. QMUR - Notification cause
4. QMSM - Notification task
5. QMMA - Notification action
The combination of sort field of item/cause, item/task and item/action must be unique within a notification. If you leave the sort field empty and the OBJTYP = QME, then a long text is created for the notification header.
Regards
Abhii

How to list an array of objects using struts in jsp and ActionForm

I am using the struts ActionForm and need to know how to display an Array of objects. I am assuming it would look like this in the ActionForm:
private AddRmvParts addRmv[];
But I am not sure how the getter and setter in the ActionForm should look. Should it be a Collection or an Iterator?
I am thinking I need to use an iterator in the jsp page to display it.
I am also wondering if the AddRmvParts class I have can be the same class that gets populated by the retrieval of data from the database. This class has 10 fields that need to display on the jsp page in 1 row and then multiple rows of these 10 fields.
Thanks.

Most probably the easiest way to make it accessible in your page is as a collection.
ie
public Collection getAddRmvParts()
You can use the <logic:iterate> or a <c:forEach>(JSTL) tag to loop through the collection
As long as the individual items in the collection provide get/set methods you can access them with the dot syntax:
Example using JSTL:
<c:forEach var="addRmvPart" items="${addRmvParts}">
<c:out value="${addRmvPart.id} ${addRmvPart.name} ${addRmvPart.description}"/>
</c:forEach>

How to create an array of linklists??? ... plz

Hi guys,
I am trying to create a Hash table. My link list is already working. But i am still confused about how to create any array linklist for solving the collisions. Do i need to create a new instance of the linklist for each array slot? What is the better way to do?
just need some hint to start it.
abdul

Yes, you need to create a new instace for each slot.
LinkedList[] ht = new LinkedList[size];
for(int x = 0; x < size; x++)
ht[x] = new LinkedList();

How to create an array variable

Hi folks,
I'm developing a flowN activity , for each branch created, I need to pass different values (values I get from DB).
For this my plan would be,
-create an array variable , load all the values(from DB) into the array
-pass the array to each branch in flowN activity based on the index
As I'm newbie to BPEL, I do not know how to create an array variable.
Could you people guide me please.
Regards
Viki

Hi,
I created my string array like
<element name="string_array">
<complexType>
<sequence>
<element name="input" type="string" minOccurs="0" maxOccurs="unbounded"/>
</sequence>
</complexType>
</element>
<variable name="arr" element="client:string_array"/>
I am able to add values to my array variable named as "arr"
When I use the following code snippet, it gives my the value of the entire list.
<%ora:getNodeValue(bpws:getVariableData('arr'))%>
But when I try retireve values one by one like <%ora:getElement('arr','/client:string_array/client:input',[0])%>, its giving me error.
Guide to get throu' this.
Viki

How to create 2D array with 3 rows and unlimit column?

how to create 2D array with 3 rows and unlimit column?

Here are images of what I described in my previous post
Message Edited by JoeLabView on 11-14-2007 07:56 AM
Attachments:
2D-array_code.PNG ‏7 KB
2D-array_values.PNG ‏13 KB

HELP! PDF objects - How to create a program line object?

Hi Experts,
I would like to know how to create a Program lines object (icon cog wheels). I need to create additional coding inside the context tab but when I try to right click on a folder --> create -->graphic,address,text,alternative...single record... No
program lines can be created.
Hope someone could help me.
Thanks,
Jeff

There are two ways of doing it, depending on what you want to accomplish. Both require that you edit the file ~/.bashrc (I assume you use bash)
1) If the application places all the executable files in a given directory (let's say /opt/Application/bin/), you can access all those executables directly by simply telling your shell where to look (in the same way the shell automatically looks for executable files in eg. /usr/bin). In ~/.bashrc, you would have to add a line that looks like this:
PATH="$PATH:/opt/Application/bin"
2) If you just want to make a traditional "shortcut" that executes a given command, this can be done with alias. Add this command to your ~/.bashrc:
alias shortcut="some command"
In this case, typing shortcut into a terminal will be interpreted just like if you had typed some command instead.
In order to try out these changes, either restart your terminal or run this command:
source ~/.bashrc
[EDIT]
I was obviously beaten to it
Last edited by Peanut (2009-05-26 23:12:47)

How to create an array of an object,

Hi,
Trying this in Oracle 10.3 studio, I have to use a web service, I have re-catalogued the web service succesfully,
I am getting compilation error whenI try to create an array of a object,
Services.PackageTrackingService.PackageTrackingItem[] pkgTrackingItem = new Services.PackageTrackingService.PackageTrackingItem[2];
I am giving the array size as 2,
The comilation error is showing as
Multiple markers at this line
- statement is expected
- Expecting ';' but 'pkgTrackingItem' was found
- expression is expected
Is there any other way to create the array?
Thanks in advance.
-Sree

Hi,
Please declare the array in following manner.
Services.PackageTrackingService.PackageTrackingItem[] pkgTrackingItem;
Now you can insert the element into the array by pkgTrackingItem[0], pkgTrackingItem[1] etc.
Bibhu

How to create an array of Vectors ?

Can I create an array of vectors in Java ? For instance I want to have an array of days in a year, an on each day there are several things to do, and I don't know this up front, so I want it to be a Vector holding the things_to_do object, some days might have nothing to do, so there should be null or an empty vector for that day. So I came up with something like the following :
Vector<Things>[] Days_Array=new Vector<Things>[365];
But Java doesn't allow this ?
Frank

Opps , I forgot to ask, although it compiled successfully, but it gave me a warning : [unchecked] unchecked conversion
I wonder if there is a way to fix it without turning the warning off, what I meant is : Am I missing something that caused the warning that I should add to the code, I don't want to turn off the warning. For instance how can I make the "conversion" checked ?
Frank

How to create an array of ArrayLists?

Hello,
I'm trying to compile the following code:
ArrayList<Object> arr[];
arr = new ArrayList<Object>()[size];in order to create an array of ArrayLists. I'm being met with the following compilation error:
The type of this expression must be an array type but it resolved to ArrayList<Object>
Can anyone show me how to correctly do this?
Thanks

{color:#3D2B1F}This line:
List<Object>[] arr = new ArrayList<Object>[5];generates the compiler error: "generic array creation" (generics and arrays don't play well together)
Since you are just parameterizing with Object, you can use non-generic collections:
List[] arr = new ArrayList[5];Me? I don't like mixing arrays and collections. I would have a list of lists:
List<List<X>> matrix = new ArrayList<List<X>>();{color}

How to create an array?

I know that when you create a new BPM object attribute you can choose an array in 10g. However, that just declares the array; I'm wondering how to allocate memory to it. I want to use it in a .jsp page for a list of fields. Also, what tag would I use to pass the parameters? i.e '<f: fieldName att="BPMObject.attribute"/>' is used for normal string variable attributes, what would I use for an array?

Hi,
Here is the code that you can write in your jsp page to iterate over an array.
     <c:forEach var="test" items="${bpmObject.bpmArray}" begin="0" varStatus="status" >
          <tr>
          <td align="center" width="25%">
          <c:out value="${test.arrayAttr1}"/></font></td>
          <td align="center" width="20%"><font size="2" face="arial">
          <c:out value="${test.arrayAttr2}"/></font></td>
          </tr>
     </c:forEach>
Bibhu
Edited by: Bibhuti Bhusan on Jul 19, 2011 8:13 PM

How to create an Array of Object

Similar Messages

Maybe you are looking for