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  • What are the characteristics of spaghetti code?

    - by justjoe
    Somebody said that when your PHP Code and application use global variable then it must be a spaghetti code (i assume this). I use wordpress a lot. As far as i know, it's the best thing near a great php software. And it use many global variables to interact between its components. but forget about that, cause frankly, that's the only thing i know. so it's completely biased ;D so just curious, What is the characteristic of spaghetti code ? ps : the only thing i know is wordpress. so, Hopefully, maybe this will help somebody give great answer for somebody who have a little experience on developing full web application on PHP (for example, stack-overflow website)

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  • Does a C++ destructor always or only sometimes call data member destructors?

    - by Magnus
    I'm trying to validate my understanding of C++ destructors. I've read many times that C++ supplies a default destructor if I don't write one myself. But does this mean that if I DO write a destructor that the compiler WON'T still provide the default cleanup of stack-allocated class fields? My hunch is that the only sane behavior would be that all class fields are destroyed no matter what, whether I provide my own destructor or not. In which case the statement I've read so many times is actually a little misleading and could be better stated as: "Whether or not you write your own destructor, the C++ compiler always writes a default destructor-like sequence to deallocate the member variables of your class. You may then specify additional deallocations or other tasks as needed by defining your own destructor" Is this correct?

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  • Compare output of program to correct program using bash script, without using text files

    - by Doug
    I've been trying to compare the output of a program to known correct output by using a bash script without piping the output of the program to a file and then using diff on the output file and a correct output file. I've tried setting the variables to the output and correct output and I believe it's been successful but I can't get the string comparison to work correctly. I may be wrong about the variable setting so it could be that. What I've been writing: TEST=`./convert testdata.txt < somesampledata.txt` CORRECT="some correct output" if [ "$TEST"!="$CORRECT" ]; then echo "failed" fi

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  • Class variable defined at @implementation rather than @interface?

    - by bitcruncher
    Hello. I'm new to Objective-C, but I am curious about something that I haven't really seen addressed anywhere else. Could anyone tell me what is the difference between a private variable that is declared at the @interface block versus a variable that is declared within the @implementation block outside of the class methods, i.e: @interface Someclass : NSObject { NSString *forExample; } @end vs. @implementation Someclass NSString *anotherExample; -(void)methodsAndSuch {} @end It seems both variables ( forExample, anotherExample ) are equally accessible throughout the class and I can't really find a difference in their behaviour. Is the second form also called an instance variable?

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  • xml and external swf documents

    - by VideoDnd
    My XML scripts work fine in the local swf. If I load an external swf, can I still retreive XML data from the same way, or do I have to declare the root somewhere? It's a general question. I know that when animating external swf files, you have to set it up differently, if so I would like an example, and a pitcher of beer. It's St. Patrick's weekend. SAMPLE CODE ONLY XML <?xml version="1.0" encoding="utf-8"?> <SESSION> <COUNT TITLE="starting position">-77777</COUNT> </SESSION> loader swf 'nodes' //grab the data as a string myString = myXML.COUNT.text(); //grab the data as an int count = int(myXML.COUNT.text()); external swf 'variables' var myString:String = ""; var count:int = int(myString); trace(count);

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  • Need help on how to begin learning website development

    - by Golfy
    OK for the past 10 days I have been trying to figure out where to begin learning website development a dynamic one, So far everyone told me you should start with computer science and I am like What the @#$% how am I suppose to learn computer science without going to school and get a degree but I don't want a degree I just want to learn how to devlope websites. So now I am here and confused about how to put together a website. I get HTML and CSS but still have some problems designing the site now on the other had I am having trouble trying to figure out how php and database mysql is used to put together a website. I have seen videos from lynda.com and still have no Idea after I have watched the video the basic one, one that teach you the Variables, Loops, Strings ext... ok than what happens, how do you build the website with it, that is the question I am real not understand the answer to. Any help will be appreciated.

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  • The C++ 'new' keyword and C

    - by Florian
    In a C header file of a library I'm using one of the variables is named 'new'. Unfortunately, I'm using this library in a C++ project and the occurence of 'new' as a variable names freaks out the compiler. I'm already using extern "C" { #include<... }, but that doesn't seem to help in this respect. Do I have to aks the library developer to change the name of that variable even though from his perspective, as a C developer, the code is absolutely fine, as 'new' is not a C keyword?

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  • C: Incompatible types?

    - by Airjoe
    #include <stdlib.h> #include <stdio.h> struct foo{ int id; char *bar; char *baz[6]; }; int main(int argc, char **argv){ struct foo f; f.id=1; char *qux[6]; f.bar=argv[0]; f.baz=qux; // Marked line return 1; } This is just some test code so ignore that qux doesn't actually have anything useful in it. I'm getting an error on the marked line, incompatible types when assigning to type ‘char *[6]’ from type ‘char **’ but both of the variables are defined as char *[6] in the code. Any insight?

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  • How to signal a buffer full state between posix threads

    - by mikip
    Hi I have two threads, the main thread 'A' is responsible for message handling between a number of processes. When thread A gets a buffer full message, it should inform thread B and pass a pointer to the buffer which thread B will then process. When thread B has finished it should inform thread A that it has finished. How do I go about implementing this using posix threads using C on linux. I have looked at conditional variables, is this the way to go? . I'm not experienced in multi threaded programming and would like some advice on the best avenue to take. Thanks

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  • How to generate DELETE statements in PL/SQL, based on the tables FK relations?

    - by The chicken in the kitchen
    Is it possible via script/tool to generate authomatically many delete statements based on the tables fk relations, using Oracle PL/SQL? In example: I have the table: CHICKEN (CHICKEN_CODE NUMBER) and there are 30 tables with fk references to its CHICKEN_CODE that I need to delete; there are also other 150 tables foreign-key-linked to that 30 tables that I need to delete first. Is there some tool/script PL/SQL that I can run in order to generate all the necessary delete statements based on the FK relations for me? (by the way, I know about cascade delete on the relations, but please pay attention: I CAN'T USE IT IN MY PRODUCTION DATABASE, because it's dangerous!) I'm using Oracle DataBase 10G R2. This is the result I've written, but it is not recursive: This is a view I have previously written, but of course it is not recursive! CREATE OR REPLACE FORCE VIEW RUN ( OWNER_1, CONSTRAINT_NAME_1, TABLE_NAME_1, TABLE_NAME, VINCOLO ) AS SELECT OWNER_1, CONSTRAINT_NAME_1, TABLE_NAME_1, TABLE_NAME, '(' || LTRIM ( EXTRACT (XMLAGG (XMLELEMENT ("x", ',' || COLUMN_NAME)), '/x/text()'), ',') || ')' VINCOLO FROM ( SELECT CON1.OWNER OWNER_1, CON1.TABLE_NAME TABLE_NAME_1, CON1.CONSTRAINT_NAME CONSTRAINT_NAME_1, CON1.DELETE_RULE, CON1.STATUS, CON.TABLE_NAME, CON.CONSTRAINT_NAME, COL.POSITION, COL.COLUMN_NAME FROM DBA_CONSTRAINTS CON, DBA_CONS_COLUMNS COL, DBA_CONSTRAINTS CON1 WHERE CON.OWNER = 'TABLE_OWNER' AND CON.TABLE_NAME = 'TABLE_OWNED' AND ( (CON.CONSTRAINT_TYPE = 'P') OR (CON.CONSTRAINT_TYPE = 'U')) AND COL.TABLE_NAME = CON1.TABLE_NAME AND COL.CONSTRAINT_NAME = CON1.CONSTRAINT_NAME --AND CON1.OWNER = CON.OWNER AND CON1.R_CONSTRAINT_NAME = CON.CONSTRAINT_NAME AND CON1.CONSTRAINT_TYPE = 'R' GROUP BY CON1.OWNER, CON1.TABLE_NAME, CON1.CONSTRAINT_NAME, CON1.DELETE_RULE, CON1.STATUS, CON.TABLE_NAME, CON.CONSTRAINT_NAME, COL.POSITION, COL.COLUMN_NAME) GROUP BY OWNER_1, CONSTRAINT_NAME_1, TABLE_NAME_1, TABLE_NAME; ... and it contains the error of using DBA_CONSTRAINTS instead of ALL_CONSTRAINTS... Please pay attention to this: http://stackoverflow.com/questions/485581/generate-delete-statement-from-foreign-key-relationships-in-sql-2008/2677145#2677145 Another user has just written it in SQL SERVER 2008, anyone is able to convert to Oracle 10G PL/SQL? I am not able to... :-( This is the code written by another user in SQL SERVER 2008: DECLARE @COLUMN_NAME AS sysname DECLARE @TABLE_NAME AS sysname DECLARE @IDValue AS int SET @COLUMN_NAME = '<Your COLUMN_NAME here>' SET @TABLE_NAME = '<Your TABLE_NAME here>' SET @IDValue = 123456789 DECLARE @sql AS varchar(max) ; WITH RELATED_COLUMNS AS ( SELECT QUOTENAME(c.TABLE_SCHEMA) + '.' + QUOTENAME(c.TABLE_NAME) AS [OBJECT_NAME] ,c.COLUMN_NAME FROM PBANKDW.INFORMATION_SCHEMA.COLUMNS AS c WITH (NOLOCK) INNER JOIN PBANKDW.INFORMATION_SCHEMA.TABLES AS t WITH (NOLOCK) ON c.TABLE_CATALOG = t.TABLE_CATALOG AND c.TABLE_SCHEMA = t.TABLE_SCHEMA AND c.TABLE_NAME = t.TABLE_NAME AND t.TABLE_TYPE = 'BASE TABLE' INNER JOIN ( SELECT rc.CONSTRAINT_CATALOG ,rc.CONSTRAINT_SCHEMA ,lkc.TABLE_NAME ,lkc.COLUMN_NAME FROM PBANKDW.INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS rc WITH (NOLOCK) INNER JOIN PBANKDW.INFORMATION_SCHEMA.KEY_COLUMN_USAGE lkc WITH (NOLOCK) ON lkc.CONSTRAINT_CATALOG = rc.CONSTRAINT_CATALOG AND lkc.CONSTRAINT_SCHEMA = rc.CONSTRAINT_SCHEMA AND lkc.CONSTRAINT_NAME = rc.CONSTRAINT_NAME INNER JOIN PBANKDW.INFORMATION_SCHEMA.TABLE_CONSTRAINTS tc WITH (NOLOCK) ON rc.CONSTRAINT_CATALOG = tc.CONSTRAINT_CATALOG AND rc.CONSTRAINT_SCHEMA = tc.CONSTRAINT_SCHEMA AND rc.UNIQUE_CONSTRAINT_NAME = tc.CONSTRAINT_NAME INNER JOIN PBANKDW.INFORMATION_SCHEMA.KEY_COLUMN_USAGE rkc WITH (NOLOCK) ON rkc.CONSTRAINT_CATALOG = tc.CONSTRAINT_CATALOG AND rkc.CONSTRAINT_SCHEMA = tc.CONSTRAINT_SCHEMA AND rkc.CONSTRAINT_NAME = tc.CONSTRAINT_NAME WHERE rkc.COLUMN_NAME = @COLUMN_NAME AND rkc.TABLE_NAME = @TABLE_NAME ) AS j ON j.CONSTRAINT_CATALOG = c.TABLE_CATALOG AND j.CONSTRAINT_SCHEMA = c.TABLE_SCHEMA AND j.TABLE_NAME = c.TABLE_NAME AND j.COLUMN_NAME = c.COLUMN_NAME ) SELECT @sql = COALESCE(@sql, '') + 'DELETE FROM ' + [OBJECT_NAME] + ' WHERE ' + [COLUMN_NAME] + ' = ' + CONVERT(varchar, @IDValue) + CHAR(13) + CHAR(10) FROM RELATED_COLUMNS PRINT @sql Thank to Charles, this is the latest not working release of the software, I have added a parameter with the OWNER because the referential integrities propagate through about 5 other Oracle users (!!!): CREATE OR REPLACE PROCEDURE delete_cascade ( parent_table VARCHAR2, parent_table_owner VARCHAR2) IS cons_name VARCHAR2 (30); tab_name VARCHAR2 (30); tab_name_owner VARCHAR2 (30); parent_cons VARCHAR2 (30); parent_col VARCHAR2 (30); delete1 VARCHAR (500); delete2 VARCHAR (500); delete_command VARCHAR (4000); CURSOR cons_cursor IS SELECT constraint_name, r_constraint_name, table_name, constraint_type FROM all_constraints WHERE constraint_type = 'R' AND r_constraint_name IN (SELECT constraint_name FROM all_constraints WHERE constraint_type IN ('P', 'U') AND table_name = parent_table AND owner = parent_table_owner) AND delete_rule = 'NO ACTION'; CURSOR tabs_cursor IS SELECT DISTINCT table_name FROM all_cons_columns WHERE constraint_name = cons_name; CURSOR child_cols_cursor IS SELECT column_name, position FROM all_cons_columns WHERE constraint_name = cons_name AND table_name = tab_name; BEGIN FOR cons IN cons_cursor LOOP cons_name := cons.constraint_name; parent_cons := cons.r_constraint_name; SELECT DISTINCT table_name, owner INTO tab_name, tab_name_owner FROM all_cons_columns WHERE constraint_name = cons_name; delete_cascade (tab_name, tab_name_owner); delete_command := ''; delete1 := ''; delete2 := ''; FOR col IN child_cols_cursor LOOP SELECT DISTINCT column_name INTO parent_col FROM all_cons_columns WHERE constraint_name = parent_cons AND position = col.position; IF delete1 IS NULL THEN delete1 := col.column_name; ELSE delete1 := delete1 || ', ' || col.column_name; END IF; IF delete2 IS NULL THEN delete2 := parent_col; ELSE delete2 := delete2 || ', ' || parent_col; END IF; END LOOP; delete_command := 'delete from ' || tab_name_owner || '.' || tab_name || ' where (' || delete1 || ') in (select ' || delete2 || ' from ' || parent_table_owner || '.' || parent_table || ');'; INSERT INTO ris VALUES (SEQUENCE_COMANDI.NEXTVAL, delete_command); COMMIT; END LOOP; END; / In the cursor CONS_CURSOR I have added the condition: AND delete_rule = 'NO ACTION'; in order to avoid deletion in case of referential integrities with DELETE_RULE = 'CASCADE' or DELETE_RULE = 'SET NULL'. Now I have tried to turn from stored procedure to stored function, but the delete statements are not correct: CREATE OR REPLACE FUNCTION deletecascade ( parent_table VARCHAR2, parent_table_owner VARCHAR2) RETURN VARCHAR2 IS cons_name VARCHAR2 (30); tab_name VARCHAR2 (30); tab_name_owner VARCHAR2 (30); parent_cons VARCHAR2 (30); parent_col VARCHAR2 (30); delete1 VARCHAR (500); delete2 VARCHAR (500); delete_command VARCHAR (4000); AT_LEAST_ONE_ITERATION NUMBER DEFAULT 0; CURSOR cons_cursor IS SELECT constraint_name, r_constraint_name, table_name, constraint_type FROM all_constraints WHERE constraint_type = 'R' AND r_constraint_name IN (SELECT constraint_name FROM all_constraints WHERE constraint_type IN ('P', 'U') AND table_name = parent_table AND owner = parent_table_owner) AND delete_rule = 'NO ACTION'; CURSOR tabs_cursor IS SELECT DISTINCT table_name FROM all_cons_columns WHERE constraint_name = cons_name; CURSOR child_cols_cursor IS SELECT column_name, position FROM all_cons_columns WHERE constraint_name = cons_name AND table_name = tab_name; BEGIN FOR cons IN cons_cursor LOOP AT_LEAST_ONE_ITERATION := 1; cons_name := cons.constraint_name; parent_cons := cons.r_constraint_name; SELECT DISTINCT table_name, owner INTO tab_name, tab_name_owner FROM all_cons_columns WHERE constraint_name = cons_name; delete1 := ''; delete2 := ''; FOR col IN child_cols_cursor LOOP SELECT DISTINCT column_name INTO parent_col FROM all_cons_columns WHERE constraint_name = parent_cons AND position = col.position; IF delete1 IS NULL THEN delete1 := col.column_name; ELSE delete1 := delete1 || ', ' || col.column_name; END IF; IF delete2 IS NULL THEN delete2 := parent_col; ELSE delete2 := delete2 || ', ' || parent_col; END IF; END LOOP; delete_command := 'delete from ' || tab_name_owner || '.' || tab_name || ' where (' || delete1 || ') in (select ' || delete2 || ' from ' || parent_table_owner || '.' || parent_table || ');' || deletecascade (tab_name, tab_name_owner); INSERT INTO ris VALUES (SEQUENCE_COMANDI.NEXTVAL, delete_command); COMMIT; END LOOP; IF AT_LEAST_ONE_ITERATION = 1 THEN RETURN ' where COD_CHICKEN = V_CHICKEN AND COD_NATION = V_NATION;'; ELSE RETURN NULL; END IF; END; / Please assume that V_CHICKEN and V_NATION are the criteria to select the CHICKEN to delete from the root table: the condition is: "where COD_CHICKEN = V_CHICKEN AND COD_NATION = V_NATION" on the root table.

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  • Integers in JavaScript

    - by muntoo
    I'm a beginner to Javascript so forgive me if I sound dumb because I learned some Javascript from W3Fools (which are really difficult tutorials - they don't explain anything I want to know, but everything I probably can guess from my experience with C++). I may be switching over to MDN, but if you can recommend any other tutorials, that be great. Anyways, so here's my question: I just read a few lines of this, and apparently: Numbers in JavaScript are "double-precision 64-bit format IEEE 754 values", according to the spec. This has some interesting consequences. There's no such thing as an integer in JavaScript, so you have to be a little careful with your arithmetic if you're used to math in C or Java. I've already seen that there are few of the data types (for variables) I'm used to from C++. But I didn't expect all numbers to automatically be floats. Isn't there any way to use integers, not float? Will a future version of JavaScript support ints?

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  • Why doesn't CSS support constants?

    - by Adiel Mittmann
    CSS has never supported constants or variables directly. Whenever I'm writing code like this: span.class1 { color: #377fb6; } div.class2 { border: solid 1px #377fb6; /* Repeated color */ } I wonder why such a seemingly simple feature has never made it into the standard. What could be hard about implementing a scheme whereby we could avoid repetition, something like this: $theme_color1: #377fb6; span.class1 { color: $theme_color1; } div.class2 { border: solid 1px $theme_color1; } I know there are workarounds, like using a class for each color or generating CSS code from templates, but my question is: given that CSS is so rich and complex, why weren't CSS constants ever introduced?

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  • Jquery: Calling functions from different documents

    - by Tom
    Hi, I've got some Jquery functions that I keep in a "custom.js" file. On some pages, I need to pass PHP variables to the Jquery so some Jquery bits need to remain in the HTML documents. However, as I'm now trying to refactor things to the minimum, I'm tripping over the following: If I put this in my custom.js: $(document).ready(function() { function sayHello() { alert("hello"); } } And this in a HTML document: <script type="text/javascript"> $(document).ready(function() { sayHello(); }); </script> ... the function doesn't get called. However, if both are placed in the HTML document, the function works fine. Is there some kind of public property I need to declare for the function or how do I get Jquery functions in my HTML to talk to external .js files? They're correctly included and work fine otherwise. Thanks.

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  • How to insert many rows of data from arrays/lists to SQL Server (DataSet, DataTable)

    - by Kamil
    I need little help with transferring data from variables, arrays, lists to my SQL Server. Im not bad in SQL, but im not familiar with DataSet, DataTable objects. My data is now stored in list of strings (List). Every string in that list looks similar to this: QWERTY,19920604,0.91,0.35,0.34,0.35,343840 There are about 900000 rows like this. Target datatypes in SQL Server: BIGINT (primary key, im not inserting it, its identity(1,1)) VARCHAR(10), DATE, DECIMAL(10,2), DECIMAL(10,2), DECIMAL(10,2), DECIMAL(10,2), INT How to convert that data to SQL Server data types? How to insert that data into SQL Server? Also i need some progress bar updates between inserts. I could do this using old-fashion SQL command, but i have learn more modern way :)

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  • Outputting variable values in x86?

    - by Airjoe
    Hello All- I'm working on a homework assignment in x86 and it isn't working as I expect (surprise surprise!). I'd like to be able to output values of variables in x86 functions to ensure that the values are what I expect them to be. Is there a simple way to do this, or is it very complex? For what it's worth, the x86 functions are being used by a C file and compiled with gcc, so if that makes it simpler that is how I'm going about it. Thanks for the help.

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  • Passing parameters to a delphi TFrame

    - by ajob
    To avoid singletons and global variables I'd like to be able to pass parameters to a TFrame component. However since a TFrame normally is included on form at design time it is only possible to use the default constructor. The parent form can of course set some properties in the OnCreate callback after the TFrame has been created. However this does not ensure that a property is not forgotten, and the dependencies are not as clear as using a constructor. A nice way would be if it was possible to register a factory for creating components while the dfm file is being read. Then the required parameters could be passed to the TFrame constructor when created by the factory. Is there a way of accomplishing this? Or does anyone have a better solution on how to pass parameters to a TFrame?

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  • Conversion of DOM element selection code to jQuery

    - by Tom McDonnell
    I have a large Javascript codebase to convert to jQuery. The code is structured such that DOM elements are created in Javascript (using a library called DomBuilder), and saved to variables if they will be needed later, before being added to the DOM. Eg. var inputs = { submitConfirm: INPUT({type: 'button', value: 'Submit'}), submitCancel : INPUT({type: 'button', value: 'Cancel'}) }; document.appendChild(inputs.submitConfirm); Then later for example... inputs.submitCancel.style.display = 'none'; inputs.submitCancel.addEventListener('click', onClickSubmitCancel, false); My problem is that jQuery seems to lack a way of manipulating DOM elements directly, as opposed to selecting them first (with for example $('#submitCancel'). Can anyone suggest a way to directly translate the last two Javascript lines given above to use jQuery, given that the DOM elements are already available, and so do not need to be selected?

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  • WCF Web/ServiceHost - Singletons and initialisation

    - by Kyle
    I have some Service class which is defined as InstanceContextMode.Single, and is well known in the hosting application. (The host creates an instance, and passes that to the WebServiceHost) Hosting app:WebServiceHost host = null; SomeService serviceInstance = new SomeService("text", "more text"); host = new WebServiceHost(serviceInstance, baseUri); Problem: When I go to use the variables initialised when the service is created (ie, when a call is made to the service), they are either null or empty... Am I wrong in assuming that as the instance being initialised in the hosting application is used for each request to the WebServiceHost? Any pointers here would be great.

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  • Does retrieving an object from Doctrine2 cause __construct() of the model class to run?

    - by jiewmeng
    When I retrieve an object say by $em->find('Application\Models\User', 1); or other methods like DQL, findBy*() cause the __construct() of the model class to run? I am having a problem where I set variables there like reference to EntityManager and I find that its not set. I tried putting a die() in __construct() and it doesn't halt the application. Can I say that if I want to set other properties/fields like EntityManager $em I have to do it some other way? Perhaps something like protected function getEm() { if (!isset($this->em)) { $this->em = \Zend_Registry::get('em'); } return $this->em; }

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  • How does an interpreter switch scope?

    - by Dox
    I'm asking this because I'm relatively new to interpreter development and I wanted to know some basic concepts before reinventing the wheel. I thought of the values of all variables stored in an array which makes the current scope, upon entering a function the array is swapped and the original array put on some sort of stack. When leaving the function the top element of the "scope stack" is popped of and used again. Is this basically right? Isn't swapping arrays (which means moving around a lot of data) not very slow and therefore not used by modern interpreters?

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  • Addslashes, mysql_real_escape always adding two slashes?

    - by Zach
    I'm having an issue with inserting JSON into a database, my intention is to take the variables, json_encode them, remove slashes (from magic_quotes), and then addslashes back in to escape the quotes in {"key":"value"} Unfortunately, strip_slashes on the encoded string isn't doing anything, and outputs this {"content":"<p>This string has it\'s downsides</p>","date":1271352514} I have then tried addslashes, and mysql_real_escape_string, both output "{\\"content\\":\\"<p>This string has it\\\'s downsides</p>\\",\\"date\\":1271352514}" I can't work out why it's adding in two slashes? And I'm tearing my hair out over this, everytime I try to stripslashes it leaves one in, and adding slashes adds two. Any help would be hugely appreciated!

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  • Mutual Information / Entropy Calculation Help

    - by Fillip
    Hi, Hoping someone can give me some pointers with this entropy problem. Say X is chosen randomly from the uniform integer distribution 0-32 (inclusive). I calculate the entropy, H(X) = 32 bits, as each Xi has equal probability of occurring. Now, say the following pseudocode executes. int r = rand(0,1); // a random integer 0 or 1 r = r * 33 + X; How would I work out the mutual information between the two variables r and X? Mutual Information is defined as I(X; Y) = H(X) - H(X|Y) but I don't really understand how to apply the conditional entropy H(X|Y) to this problem. Thanks

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  • How do you refresh the contents of an R gWidget?

    - by Richie Cotton
    I'm creating a GUI in R using gWidgets (more specifically gWidgetstcltk). I'd like to know how to update the contents of selection-type widgets, such as gdroplist and gtable. I currently have a rather hackish method of deleting the widget and re-creating it. I'm sure there's a better way. This simple example displays all the variables in the global environment. library(gWidgets) library(gWidgetstcltk) create.widgets <- function() { grp <- ggroup(container = win) ddl <- gdroplist(ls(envir = globalenv()), container = grp) refresh <- gimage("refresh", dirname = "stock", container = grp, handler = function(h, ...) { if(exists("grp") && !is.null(grp)) { delete(win, grp) rm(grp) } grp <- create.widgets() } ) } win <- gwindow() grp <- create.widgets()

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  • How to use regular expression and assign result into valuables in Android??

    - by user304078
    Dear all, I have to say sorry for my poor English first... I have a string named s_Result which will be parsed from Internet, the format may be "Distance: 2.8km (about 9 mins)", and there are 4 variables which are f_Distance, m_DistanceUnit, f_timeEst, m_timeEstUnit. My question is, how to parse s_Result and assign 2.8, km, 9, mins into f_Distance, m_distanceUnit, f_timeEst, and m_timeEstUnit respectively using regular expression?? I tried using "\d+(.\d+)?" in RegEx Tester and the result showed 2 matches found, but if use "\\d+(\\.\\d+)?" in Android code, it showed nothing matched!!! Is there any suggestion?? Thanks for your help!!

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  • PHP Sessions - Locking and Sharing questions

    - by Nuno Peralta
    Hi, I would like to know if it is possible to read $_SESSION attributes without locking it. Currently, session_start() locks SESSION, that means other PHP processes will wait until it is unlocked. But, some processes just want to get some $_SESSION variables, not to write on them. Is that possible to implement some function like session_get(string $id) which doesn't lock SESSION? Also, it is possible to share SESSIONs between browsers, once the user is logged in the same account, for example, using session_id('shared_vars_of_'.$userid). But, is that secure? Is this discouraged? Thanks, Nuno

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