Search Results

Search found 11015 results on 441 pages for 'explain plan'.

Page 308/441 | < Previous Page | 304 305 306 307 308 309 310 311 312 313 314 315  | Next Page >

• Property and Encapsulation

  - by Lijo

  Hi Team, Following is a question regarding using Properties in class. I am software engineer with 3 years of experience. I have been using public properties instead of exposing member variables publically. Many a people told that this approach helps in encapsulation. I don’t realize any encapsulation advantage by making it a property. While discussions, I came to know that not many people knows about the real reason for going for Property. They just do it as part of coding standard. Can someone clearly explain how Property is better than public member variable? How it improves encapsulation? Thanks Lijo

  Read the article

• question about copy constructor

  - by lego69

  I have this class: class A { private: int player; public: A(int initPlayer = 0); A(const A&); A& operator=(const A&); ~A(); void foo() const; }; and I have function which contains this row: A *pa1 = new A(a2); can somebody please explain what exactly is going on, when I call A(a2) compiler calls copy constructor or constructor, thanks in advance

  Read the article

• MySql query and table optimisation

  - by Cheeky

  Hi everyone. I am trying to run the following simple query on a table with 500K records. SELECT COUNT(*) AS impressionCount FROM impression WHERE 0 = 0 AND impressionObjectId1 = 'C69A54B8-B828-E2E4-2319A93011DF4120' AND impressionObjectId2 = '1'; This query is taking 10 seconds to run. I have tried creating individual indexes for the impressionObjectId1 and impressionObjectId2 columns, as well as a composite index using both. The composite worked well for a while, but now it is also slow. Here is my table structure: DROP TABLE IF EXISTS `impression`; CREATE TABLE `impression` ( `impressionId` varchar(50) NOT NULL, `impressionObjectId1` varchar(50) NOT NULL, `impressionObjectId2` varchar(50) default NULL, `impressionStampDate` datetime NOT NULL, PRIMARY KEY (`impressionId`), KEY `IX_object` (`impressionObjectId1`,`impressionObjectId2`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 ROW_FORMAT=DYNAMIC COMMENT='InnoDB free: 191488 kB'; Any advice would be greatly appreciated. Thanks EDIT: When adding an EXPLAIN, this is the output: 1, 'SIMPLE', 'impression', 'ref', 'IX_object', 'IX_object', '105', 'const,const', 304499, 'Using where; Using index'

  Read the article

• Reference and Value confusion

  - by rgamber

  Hi I read this question on Stack overflow, and tried to do an example. I had the below code: public static void main(String[] args){ int i = 5; Integer I = new Integer(5); increasePrimitive(i); increaseObject(I); System.out.println(i); //Prints 5 - correct System.out.println(I); //Still prints 5 System.out.println(increaseObject2(I)); //Still prints 5 } public static void increasePrimitive(int n){ n++; } public static void increaseObject(Integer n){ n++; } public static int increaseObject2(Integer n){ return n++; } Does the increaseObject print 5 because the value of reference is changing inside that function? Am I right? I am confused why the increasedObject2 prints 5 and not 6. Can anyone please explain?

  Read the article

• Java Thread wait() => blocked?

  - by Chris

  According to http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Thread.State.html calling wait() will result a thread to go in BLOCKED state. However this piece of code will result (after being called) in a Thread in WAITING State. class bThread extends Thread { public synchronized void run() { try { wait(); } catch (InterruptedException e) { e.printStackTrace(); } } } Have I got something wrong? Can anybody explain this behaviour to me? Any help would be appreciated!

  Read the article

• Regular expression problem

  - by sYl3r

  Hi, How can I search a whole string for a specific match. It'll contain both characters with int or decimal numbers eg A12B32.25C-456D-75.E75 I'll know that this will start with A and ends with E I think I can use "^" and "$" right? but i'm bit lost in other parts to check for character and int or decimal. I'll be glad if you can give the regex and explain it a bit :). PS. D-75. is not mistyped... Thanks in advance.

  Read the article

• Can typeid() be used to pass a function?

  - by Kerb_z

  I tried this and got the output as: void Please explain the following Code: #include <cstdio> #include <typeinfo> using namespace std ; void foo() { } int main(void) { printf("%s", typeid(foo()).name());// Please notice this line, is it same as typeid( ).name() ? return 0; } AFAIK: The typeid operator allows the type of an object to be determined at run time. So, does this sample code tell us that a function that returns void is of *type void*. I mean a function is a method and has no type. Correct?

  Read the article

• iPhone App on iPad - What is the extra effort?

  - by hol

  I started to develop an iPhone App for a client but the binary not yet submitted to Apple. My client asked me whether they can run the iPhone App also on the iPad. I am not sure what to answer. I am away from home and cannot even check how this all works in XCode. I wonder whether I have to submit two binaries two Apple - one for iPhone and one for iPad - or how this all works? If somebody with experience can explain me. Basically I need to figure out how much more effort I have to consider if it is only making the app work on the iPad. I do not mean the effort to redesign the whole app being a real "iPad app". Just to make it work and when somebody downloads the app and it can be for an iPhone and for an iPad and it does not matter.

  Read the article

• Javascript: Retrieve Object Property Names

  - by Jason

  I'm trying to write a function that needs to know the property names of an object being passed in, like so: var data = { "key1":"value1", "key2":"value2", etc} ^ i want the string value "key1" How do I retrieve the string "key1" from data? I know I can set a property dynamically like data[prop]=value but i want to know what prop is from an object passed in. If that doesn't make sense I suppose I could try to explain more. Thanks! I eventually want to do something like: for (var i = 0; i<data.length; i++) { var name = data[i].getPropertyName() <--- not a real function // do stuff }

  Read the article

• *(char**) how to understand this construct?

  - by House.Lee

  recently, while reading former's code in my current project, I encounter the problems below: while implementing the Queue, my former wrote codes like this: while(uq->pHead) { char *tmp = uq->pHead; uq->pHead = *(char **)tmp; //... } the uq-pHead has definition like: typedef struct { char* pHead; //... } Queue; Well, I'm quite confused about the usage that "uq->pHead = *(char**)tmp" , could anyone explain it to me in detail? if we assume that *(uq-pHead) = 32(i.e. ' ') , *(char**)tmp would translate this into pointer-form, but...how could it make sense? Thanks a lot.

  Read the article

• algorithms undirected graph twodegree[]

  - by notamathwiz

  For each node u in an undirected graph, let twodegree[u] be the sum of the degrees of u's neighbors. Show how to compute the entire array of twodegree[.] values in linear time, given a graph in adjacency list format. This is the solution for all u ? V : degree[u] = 0 for all (u; w) ? E: degree[u] = degree[u] + 1 for all u ? V : twodegree[u] = 0 for all (u; w) ? E: twodegree[u] = twodegree[u] + degree[w] can someone explain what degree[u] does in this case and how twodegree[u] = twodegree[u] + degree[w] is supposed to be the sum of the degrees of u's neighbors?

  Read the article

• Is it possible in Java to implement something similar to Object.clone() ?

  - by devoured elysium

  The Object.clone() method in Java is pretty special, as instead of returning a copy of the object that is to be cloned with the Object type, it returns the correct Object type. This can be better described with the following code: class A extends Object { public A clone() { return super.clone(); //although Object.clone() is from the Object class //this super.clone() will return an A object! } } class B extends A { } public static void main(String[] args) { B = new B(); B.clone();//here, although we haven't defined a clone() method, the cloned //object return is of type B! } So, could anyone explain if possible if is there anyway to replicate what happens inside Object.clone()'s method?

  Read the article

• About Attributes member of LUID_AND_ATTRIBUTES used in TOKEN_PRIVILEGES structure

  - by Astaroth

  MSDN article, Enabling and Disabling Privileges in C++, provided the a code example to show how to enable or disable a privilege in an access token. I quote the part in questioned: tp.PrivilegeCount = 1; tp.Privileges[0].Luid = luid; if (bEnablePrivilege) tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED; else tp.Privileges[0].Attributes = 0; What is the meaning of zero value for Attributes member? According to the documentation of TOKEN_PRIVILEGES structure, the attributes of a privilege can be a combination of the following values: SE_PRIVILEGE_ENABLED  (it is 0x00000002L in WinNT.h) SE_PRIVILEGE_ENABLED_BY_DEFAULT  (it is 0x00000001L in WinNT.h) SE_PRIVILEGE_REMOVED  (it is 0x00000004L in WinNT.h) SE_PRIVILEGE_USED_FOR_ACCESS  (it is 0x80000000L in WinNT.h) So, we don't see any valid constant with a value of zero. I guess, the zero is equal to SE_PRIVILEGE_REMOVED. Anybody here could explain what the zero value really does?

  Read the article

• c++ possible errors

  - by lego69

  hello I've got error a1 was not declared in this scope, can somebody please explain me my fault my header: #ifndef QUIZ_H_ #define QUIZ_H_ #include "quiz.cpp" class A { private: int player; public: A(int initPlayer); ~A(); void foo(); }; #endif /* QUIZ_H_ */ implementation of class functions: #include "quiz.h" #include <iostream> using std::cout; using std::endl; A::A(int initPlayer = 0){ player = initPlayer; } A::~A(){ } void A::foo(){ cout << player; } my main #include "quiz.h" int main() { quiz(7); return 0; } function quiz: #include "quiz.h" void quiz(int i) { A a1(i); a1.foo(); }

  Read the article

• functionality of cin in c++

  - by wyatt

  I'm a bit confused by the results of the following function: int main() { string command; while(1) { cin >> command; if(command == "end") return 0; else cout << "Could you repeat the command?" << endl; } return 0; } First of all - the output line ("could you...") repeats once for each individual word in the input (stored in command). So far as I can see, it should only be possible for it to happen once for each instance of the loop. Also, when the line 'if(command == "end")' is changed to 'if(command == "that's all")' it never triggers. A little testing suggested that all of the whitespace was removed from the command. Could someone explain to me what's going on here? Thanks

  Read the article

• Solution to grab text from page and display it elsewhere?

  - by GaryW

  I am trying to find a solution how to grab a text from one part of the page to be displayed on a different part of the same page (not stored). To explain this easier. I have this: <div id="test"> hello world </div> I want to grab the text "hello world" and display it somewhere else on the website as well. Im thinking that there might be a javascript code that could grab that specific div text? Any help would be very appreciated.

  Read the article

• Visual Studio C++ adds "junk" to my programs

  - by sub

  I have looked into the binaries produced by MSVC 2010 from my source code, and saw everything being filled with "junk". I don't know how to explain, but my executables are being added too much unnecessary information, like: Lots of Microsoft default error messages, I don't want them XML schema settings (Why!?) Other things not important for the execution of the main program How can I stop MSVC doing this? Do I have to switch to GCC? In all other programs (written in C++ too, from Word processors to games), this junk simply doesn't exist.

  Read the article

• JQuery or Javascript solution for selecting default value in drop down

  - by user1446843

  I have a calender list in a webpart page, this webpart page has a version number in it's title e.g. "WebPart 1.62". What I need to do is when a New item is created in the calender list on a webpart page, the New Item form has a dropdown menu 'SystemID' which gets it's values from the title column of a 'Systems' list, which is pre-populated with all versions of webpart forms. This dropdown menu 'SystemID' should select the version of the webpart page it is in as the default value. I need a JQuery solution for this, or even Javascript. I am finding it difficult as I am new to both JQuery and Sharepoint. I am using SP2007. I'll appreciate any guidance in solving this. At the moment the Create New Item form of the Calender list has the 'SystemID' drop down list pre-populated with the versions from the Systems list. If anyhthing is unclear pls let me know and I'll explain in more detail.

  Read the article

• Linq - Grouping where items fall in multiple groups?

  - by PirateKitten

  Is it possible using Linq to create a group where items fall into more than one group? Using the following trivial example: public class Data { public string ID; public int From; public int To; } And this list: List<Data> data = new List<Data>() { new Data() { ID = "A", From = 1, To = 3 }, // Call this A new Data() { ID = "B", From = 1, To = 2 }, // Call this B new Data() { ID = "C", From = 2, To = 3 } // Call this C }; I'd like to group by each possible integer in the ranges From and To (though instead of finding the min + max I could supply the query with the range I want, for example 1 to 3), and in each group would be a reference to the Data instance where the grouping int fits in its range. Hard to explain, easier to show each group and the instances I'd expect in each: [Group 1] 1 - A, B [Group 2] 2 - A, B, C [Group 3] 3 - A, C Is this possible? Or must groups be mutually exclusive?

  Read the article

• how to read hindi text from a file in c++ ??

  - by yogeshbablu

  A file contains hindi text. I want to read this file and perform some operations on text it contains. So, if anyone could please explain how to read it from file and handle it(or just print it). Ex: if file contains ?? ?? ?????? ???? then my program should read this content from file and print above text on standard output. I want to perform it on Linux. Direct code will be more beneficial.

  Read the article

• is it right way( safe) to assign post data value directly by name attibute value to a variable in

  - by I Like PHP

  i m working in PHP since one year, but now a days i got this way to assign post data value directly using name attribute . i m really curious to know the documentation about it.please refere me link regarding this . i explain by example here is my form <form method="post" action=""> <input type="text" name="userName" id="userName"> <input type="submit" name="doit" value="submit"> </form> to get the post data i always use $somevar=mysql_real_escape_string($_POST['userName']); but now i see another way $somevar= "userName"; i just want to know that is it safe n easy way??

  Read the article

• Confusing calling method in Java

  - by vBx

  class Parent { private void method1() { System.out.println("Parent's method1()"); } public void method2() { System.out.println("Parent's method2()"); method1(); } } class Child extends Parent { public void method1() { System.out.println("Child's method1()"); } } class test { public static void main(String args[]) { Parent p = new Child(); p.method2(); } } I'm confuse why does in Parent::method2() when invoking method1() it will cal Parents method1() and not Childs method1 ? I see that this happens only when method1() is private? Can someone explain me why ? Thanks you.

  Read the article

• PHP MySQL query string

  - by user1174762

  I am newer to PHP and MySQL and I am having trouble understanding join. I think, for me, the problem lies with actually understanding the logic of the query. What I am trying to do Is select all of the status updates from a table named "post", but only ones from users I am "following", and then display them In order by date. So, I have two databases which are set up like so: posts |post_id|user_id|post_body|date_upload| | 1 | 4 | hey. | 01/2/2012 | follows |relation_id|user_id|followee_id| | 1 | 4 | 2 | Could someone please explain how I should syntactically and Logically set this up? Thank you!

  Read the article

• Reversing linked list C

  - by user2976389

  node *rever(node *root) { node *prev = NULL; node *xnew = NULL; while (root != NULL) { xnew = malloc(sizeof(root)); xnew->value = root->value; xnew->next = prev; prev = xnew; root = root->next; } return xnew; } Hello I wrote this linked list reverse function. However it doesn't work(empty response): I suspect it's because of prev index getting overwritten. Could someone explain me whats going on? I know I could find working code on the internet but I wanna know what am I doing wrong. Thanks

  Read the article

• I have a Segmentation fault (core dumped) when using strcpy, malloc, and struct

  - by malsh002

  Okay, when I run this code, I have a segmentation fault #include<stdio.h> #include<stdlib.h> #include<string.h> #define MAX 64 struct example { char *name; }; int main() { struct example *s = malloc (MAX); strcpy(s->name ,"Hello World!!"); return !printf("%s\n", s->name); } the terminal output: alshamlan@alshamlan-VGN-CR520E:/tmp/interview$ make q1 cc -Wall -g q1.c -o q1 alshamlan@alshamlan-VGN-CR520E:/tmp/interview$ ./q1 Segmentation fault (core dumped) alshamlan@alshamlan-VGN-CR520E:/tmp/interview$ gedit q1.c Can someone explain what's going on? thanks.

  Read the article

< Previous Page | 304 305 306 307 308 309 310 311 312 313 314 315  | Next Page >