Storing local variables

Sorry for the simplicity of this question!
If my script runs within a master function/object - all the variables are held within that object (declared locally )so don't affect the global namespace.
When I look at other people's scripts - I see they define their vars as part of a data object - just wondering is this just good, tidy practice or is there something I am not getting?
Cheers.
A

Hey Alan,
it makes no difference, except that if you add your variables to the main object you can call them from "outside" the function in which they were created after it is done running.

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How to declare local variables in PL/SQL stored programs

Where do I declare local variables in a PL/SQL stored program?
I get compiler errors with either of the options below:
FUNCTION GET_PRINCIPAL_BALANCE (CUT_OFF_DATE IN DATE, TITLE_SN IN DATE, TOTAL_BALANCE OUT NUMBER) RETURN NUMBER IS
TOTAL_BALANCE NUMBER;
BEGIN
RETURN TOTAL_BALANCE;
END;
FUNCTION GET_PRINCIPAL_BALANCE (CUT_OFF_DATE IN DATE, TITLE_SN IN DATE, TOTAL_BALANCE OUT NUMBER) RETURN NUMBER IS
BEGIN
TOTAL_BALANCE NUMBER;
RETURN TOTAL_BALANCE;
END;

Your local variable cannot have the same name as the formal out parameter. This is a procedure example, but since functions should not have out parameters anyway ...
session2> CREATE PROCEDURE p (p_id IN NUMBER, p_did OUT NUMBER) AS
2     p_did NUMBER;
3 BEGIN
4     p_did := p_id * 2;
5 END;
6 /
Warning: Procedure created with compilation errors.
session2> show error
Errors for PROCEDURE P:
LINE/COL ERROR
0/0      PL/SQL: Compilation unit analysis terminated
1/1      PLS-00410: duplicate fields in RECORD,TABLE or argument list are
         not permittedThe proper way to create a function would be something like:
CREATE FUNCTION f (p_id IN NUMBER) RETURN NUMBER AS
   l_did NUMBER;
BEGIN
l_did := p_id * 2;
RETURN l_did;
END;You should really assign a value to the variable before you return it.
John

SQL environment variable into a local variable in stored procedure ?

How do i set a SQL environment variable in a session ? How can i read an SQL environment variable into a local variable declared in my stored procedure ? Does any exceptions occur in the process ?
I need this very urgently, can anyone help ?
thanks
srini

You can use a pipelined table function to return it, which is covered here:
http://blog.mclaughlinsoftware.com/plsql-programming/pipelined-functions-plsql-tables/
Alternatively, you can use a SQL Object type wrapped by a collection of that SQL object type inside a TABLE call. I've blogged on that too, here:
http://blog.mclaughlinsoftware.com/2009/03/23/object-record-collections/
If you need something more, leave a comment on the blog. I'm not here on the forum too frequently. Hope that helped.

Why local variables are stored on stack?

Hi,
Can anyone tell why local variables are stored on stack and objects on heap?
Thanks
Neha

paulcw wrote:
I'm pretty sure that Java doesn't store any objects on the stack.I wouldn't be so sure if I were you.
Why wouldn't Java be open to possible optimizations? It's definately faster to keep an object on the stack than letting it go through the garbage collector.
In fact the Java compiler from Sun has had this optimization in the pipeline for a long time. I'm sure it's due "anytime soon" now.
So it's wrong to say that objects are always stored on the heap. They can be store on the stack if it can be proved that their lifetime is limited to that of a method call. This requires the compiler to perform a so called "escape analysis" which has been in place for a long time in Sun compilers.
If you want to learn more, Google for "escape analysis".

How can I put the contents of an array into a set of write local variable clusters?

I have a set of controls that a user fills in. The controls are clustered by rows, then combined into a 1D array, then written to a file. When I read the file, I want to feed the array back into the clusters with write local variables. Is there a simple way to handle the numerous local variable clusters so I can stuff the array back into them?
Is there a better way to handle the whole issue of storing and recovering the information?
The rows are steps in a procedure, and each row (cluster) contains numerical as well as string controls.

There are many ways of doing this
You may convert all your data to strings and save as an ascii file (you have to pay attention to the file format, so you can read it properly.
Or you can use the configuration vi's, it may work in your case.
or you may use an invoke node to get all controls of the vi's, save it, then read it, without worrying about any format. I have attached a vi that uses this method.
Attachments:
Temp.vi ‏52 KB

Error in assigning value to local variable

i am writing a stored procedure in which i have pass parameter if parameter value is zero then i assign a previously declared variable null else that value
syntax is this
create or replace
PROCEDURE usp_Add_Update_Insurance
p_CityID IN NUMBER DEFAULT NULL
as
v_CityID number(10,0);
begin
IF p_CityID = 0 THEN
BEGIN
v_CityID := NULL;-----giving error in this line
else
v_CityID:=p_CityID;
END;
END IF;
end
begin
///some query
end
please help someone

I think there is no added value by putting those Begin/End.
The simplest solution is just remove them
Create Or Replace
Procedure Usp_Add_Update_Insurance (
     P_Cityid In Number Default Null
) As
     V_Cityid Number(10,0);
Begin
     If P_Cityid = 0 Then
          V_Cityid := Null;
     Else
          V_Cityid:=P_Cityid;
     End If;
     -- do something with V_Cityid
End; The only reason for having Begin/End is if you want to catch some exceptions or perform some strange local variable declarations. But it does not seems to be case here.
MJ

What is it about data types of local variables?

Hey there!
I'm trying hard to access the booleans, whose refnums got stored into an array. As the example show, everything's fine unless I start using local variables: I can access the data in the topmost FOR loop. As soon as variables come into play, it seems as if I have to explicitly typecast the data. Is it just me? There has to be a less complicated way... can anybody give me a hint?
Kind regards,
Severin
Attachments:
data types of local variables.jpg ‏96 KB
data types of local variables_7.11.vi ‏39 KB

Hi Severin,
The output from that property node is of variant data type. You can convert it to boolean by using the Variant to Data VI. See attached example
Sarah
Applications Engineer | National Instruments | UK & Ireland
Attachments:
data types of local variables_7.11.vi ‏41 KB

Local variable problem

I am making an application that takes an apartment number and number of occupants in that apartment and then displays a number of statistics. So far I haven't had much problem
except on a what is probably a very simple problem.
I have two buttons, and when "store" is clicked the info in the textboxes is input to an array.
My problem is with the next button, "quit", this is where all the info is supposed to be displayed.
All my variables that I need from "store" are local and are recognized in " the if statement in quit. Ive tried declaring them outside of the if statement, but it hasn't been working.
{code}
public void actionPerformed(ActionEvent event)
               Object source = event.getSource();
               Apartment input;
               if (source == store)
                    Integer aptNo = Integer.parseInt(input1.getText());
                    Integer occup = Integer.parseInt(input2.getText());
                    input = new Apartment(aptNo, occup);
                    if(aptNo > BUILDING_SIZE)
                         JOptionPane.showMessageDialog(null, "That apartment number doesn't exist.");
                    else if(occup > MAX_OCCUPANTS)
                         JOptionPane.showMessageDialog(null, "Too many occupants, only 20 are permitted per apartment.");
                    else
                         occupants[aptNo] = occup;
                         input1.setText("");
                         input2.setText("");
                         JOptionPane.showMessageDialog(null, input.getNumber(occupants));
               if (source == quit)
               // I need the variables aptNo and occup in here to put into my methods for output, but I don't know how to get them.
{code}

EmmCeeVee wrote:
Thank you for all of the responses, it really helps me out.
Obviously my knowledge of local variables is hurting as I switched it around as your said and declared the aptNo and occup outside of the if's.
All I need is for the quit button to look at the array ( which has just been modified by the sotre button) and output a bunch of results.
Heres where im at:Your problem is of scope of the variables.
Here whatever variable you defined in actionPerformed they are local for that method (they are out of scope when the method is finished/called again), Upon this, the actionPerformed is called twice one for store and another time for quit. So you cant expect the value stored at store should be there still when you all quit
If you want those values available on both the actions then make them a class level variables.
Below is a sample program, might help you.
class Employee
     String empName = null;
     int empNo;
     Employee(String eName,int eNmbr)
          this.empName = eName;
          this.empNo = eNmbr;
class CheckVariableScope
        Employee empOb; // Here
     int eNo;
     String eName = null;
     public void checkScope(String action)
                //Instead of defining Employee reference variable, eNo and eName in checkScope method, define it @ class level.
                // in your case they are Apartment input, Integer aptNo and Integer occup
                 // like above i did.
                 // If i comment the class level variable and uncomment method variable, this program also give the same error.
          //Employee empOb;
          //int eNo;
          //String eName = null;
          if (action.equals("Store") )
                    eNo = 10;
                    eName = "Bob";
                    empOb = new Employee(eName, eNo);
                    System.out.println("The eName is : "+empOb.empName+" , empNo is : "+empOb.empNo);
               if (action.equals("quit"))
                    System.out.println(" eNO from Object is : "+empOb.empNo);
                    System.out.println(eNo); //Error: may not have been intitialized
     public static void main (String st[])
          CheckVariableScope ob = new CheckVariableScope();
          ob.checkScope("Store");
          ob.checkScope("quit");
}

How to specify a unique integer for each local variable defined in TestStand?

I have a .net application that reads all TestStand local variables, but for the .net application each local variable should have a unique integer number. Iterating through the locals and storing the index is not a good solution, because if a local variable is moved or deleted, the index will change.
Does anyone know how to do this in TestStand or having an idea how to this in my .net application?
Thanks.

Thanks Doug for your reply. Using a GUID is not an option because this ID is too long. I will try to explain why I need this ID for. I have a lot of C# code that generates code to deal with a lot of instruments. For example to configure a device, user defined variables can be used to specify some settings or to store results. These variables are not stored in the generated code with a name but with an integer number. Now I want to try to be use all our existing device driver code with the TestStand sequencer. So, I need a translation between the name of a TestStand local variable and an integer number. After constructing the interface to my code I want to read all the variables from TestStand and now I need the integer ID to do the mapping to my variables. I know that I can use use your proposition 2 by encoding the unique ID into the name of the variable and parse the name of the variable to get it back, but this is not an automated way. This will be rather difficult if there are several hundreds of variables. For this reason I am looking for an alternative way. Looking forward for your response. Best regards

Are all local variables indexed consecutively?

Dear All,
In JVM, each frame contains an array of variables addressed by indexing. I am wondering if all local variables must be stored consecutively in the array.
For example, is it possible for this scenario to happen:
The length of the local variable array is 10, and a compiler translates 3 local variables of type Object to be located at index 3, 5, and 8 respectively (assuming no parameters in their enclosing method)?
The reason I need to know this is because I am using ASM to transform bytecode and need to introduce my own local variables. If all local variables' indices must be consecutive, I can get the max. number of locals (3 in the above example) of the original method and give my new locals indices starting from 4, ... But if they are not consecutively indexed, I have to use other ways.
Your help is much appreciated,
-- Sunny

Therefor my other question is: does max_locals
represent the length of the local variable array, or
does it mean the number of local variables that are
actually exist in the array? Thanks again.It gives the number of local variables in the local variable array but long and double are each considered to reserve two local variables and contribute two units toward the max_locals value.

Parameters, attributes, local variables...quick question...

could these all be called the same name within a single jsp since they are stored in different scopes? I keep getting inconclusive results on my testing. Thank you very much for taking the time to read this question.

Yes, you can have a request parameter, a session attribute, and a local variable all named the same thing. That is, it's legal as far as Java, JSP, and servlets are concerned. However, I believe some tag libraries will look for beans in the request first and then in the session if not found there, or something like that, so in the context of those taglibs, one of the values will hide the other.

Camera image as local variable

Hey,
I am looking to use the same image out reference for each of my camera inspections. I take an image at the start of my test i call this camera image1, later on i perform numerous test inspections, however, my camera1 image is blank for the first 5 steps but displays an image for 3 steps then gives a blank image at the end again. I created a local variable of the image out reference. Any suggestions helpful. Thank you.
Damien
Solved!
Go to Solution.

Hi Damien129,
Are you able to upload your VI here for me to take a look at.
Something to bare in mind is that the value from image out is not an image. The value is a refernce to the temporary memory location where that image is stored.
Kind Regards
Kevin R
Applications Engineer
National Instruments UK&Ireland

What is difference between local variable and property node ?

What is difference between local variable and property node ?
" 一天到晚游泳的鱼"
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To make things clear, here are two small examples that show how nasty locals and value properties can be to the naive programmer.
- Open the diagram of the race condition.vi before running it and try to predict what will be the values of the two counters after the third run.
- Use the Compare Locals Properties and Wires.vi to find out how slow locals and value properties can be (times 1000+).
This being demonstrated, I must add that I use globals and value properties quite often, because they are often very convenient
Chilly Charly (aka CC)
E-List Master - Kudos glutton - Press the yellow button on the left...
Attachments:
Race condition.vi ‏9 KB
Compare Locals Properties and Wires.vi ‏18 KB

How to use local variable in member formula?

Hi Expert,
We would like to use a {local variable} in a member formula, so that it can pick up the prompt from webform upon save. Would like to know if it is possible to do? If so, what is the correct syntax?
We attempted to use brace {scenario}, blacket [scenario], blacket with quote ["scenario"]. None of these work.
We are using 11.1.2.1 version, EPMA, Hyperion Planning.
Thanks in advance for your help!

One other pointer. Where did you define your variable? Hopefully you went into Calc Manager and selected <Tools>, <Variables>. From there, navigate to your application or database. Right-click on your application or database and select "New". In the bottom panel, you'll need to select your Variable Type. Make sure you select "Member", and not "Members". You cannot pass "Members" (plural) to a web input form. Also, if you want to define a variable for a custom dimension, you'll need to do it at the database level. Standard dimension member variables can be defined at the app level. (Not sure why this is the case, especially when my custom dimension exists in all plan types . . . . )
Anyway, hope this helps,
- Jake

Default initialisation of member variables and local variables

I don't understand why member variables are initialized with default values by Java.
Objects are initialized with "null" and primitives with "0", except boolean, which is initialized with "false".
If these variables are used locally they are not initialized. The compiler requires them to be initialized by the programer, for example "String s = null".
Why? What is the use of that difference?
And why are arrays always initialized with default values, no matter if they are member variables or local variables? For example String[] s = new String[10]; s[0] to s[9] are initialized with "null", no matter if "s" is a local or member variable.
Can someone please explain that strange difference, why it is used? To me it has no sense.

Most of the time I have to initialize a local variable
with "String s = null" in order to use it because
otherwise the compile would complain. This is a cheap
little trick, but I think everyone uses it.
I wouldn't agree with "most of the time". The only cases where it is almost necessary to do that is when the variable should be initialized in a loop or a try-catch statement, and that doesn't happen too often.
If local variables were initiliazed automatically without a warning it would be a Bad Thing: the compiler could tell when there is a possibility that a variable hasn't been assigned to and prevent manymanymany NullPointerExceptions on run time.
And you didn't answer me why this principle is not
used with arrays if it is so useful as you think.
Possibly it is much more difficult to analyse the situation in the case of arrays; what if values are assigned to the elements in an order that depends on run time properties such as values returned from a random number generator.
The more special rules one has to remember, the more
likely one makes errors.I agree, but what is the rule to remember in this case?

Storing local variables

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