Search Results

Search found 9082 results on 364 pages for 'c functions'.

Page 157/364 | < Previous Page | 153 154 155 156 157 158 159 160 161 162 163 164  | Next Page >

  • How do you return a pointer to a base class with a virtual function?

    - by Nick Sweet
    I have a base class called Element, a derived class called Vector, and I'm trying to redefine two virtual functions from Element in Vector. //element.h template <class T> class Element { public: Element(); virtual Element& plus(const Element&); virtual Element& minus(const Element&); }; and in another file //Vector.h #include "Element.h" template <class T> class Vector: public Element<T> { T x, y, z; public: //constructors Vector(); Vector(const T& x, const T& y = 0, const T& z =0); Vector(const Vector& u); ... //operations Element<T>& plus(const Element<T>& v) const; Element<T>& minus(const Element<T>& v) const; ... }; //sum template <class T> Element<T>& Vector<T>::plus(const Element<T>& v) const { Element<T>* ret = new Vector((x + v.x), (y + v.y), (z + v.z)); return *ret; } //difference template <class T> Element<T>& Vector<T>::minus(const Element<T>& v) const { Vector<T>* ret = new Vector((x - v.x), (y - v.y), (z - v.z)); return *ret; } but I always get error: 'const class Element' has no member named 'getx' So, can I define my virtual functions to take Vector& as an argument instead, or is there a way for me to access the data members of Vector through a pointer to Element? I'm still fairly new to inheritance polymorphism, fyi.

    Read the article

  • How do I use multiple where clauses in GHCi?

    - by T.R.
    I'm playing around with GHCi for the first time, and I'm having some trouble writing multi-line functions. My code is as follows: Prelude> :{ Prelude| let diffSquares lst = abs $ squareOfSums lst - sumOfSquares lst Prelude| where Prelude| squareOfSums lst = (fst (sumsAndSquares lst))^2 Prelude| sumOfSquares lst = snd (sumsAndSquares lst) Prelude| sumsAndSquares = foldl (\(sms,sqrs) x -> (sms+x,sqrs+x^2)) (0,0) Prelude| :} It gives the following error: <interactive>:1:142: parse error on input `=' Could someone kindly point me in the direction of what I'm missing?

    Read the article

  • Jump to function declaration in php

    - by aeonsleo
    HI, I have the following ide's for php Dreamweaver php-Eclipse Textpad I wish to jump to a function's definition which is located in another file which is not yet open. How could I do that. I am studying a websites code and have the entire directory struction in my local root folder. I come accross certain functions and I dont know in which file their definition is. Pls suggest something.Thanks

    Read the article

  • mysql_query -- question about results "location"

    - by Andrew Heath
    Forgive me if this is a particularly stupid question! mysql_query($query) returns a boolean, but you can also assign it to a variable $results = mysql_query($query) and then use the other mysql_ functions to extract data. Out of curiosity, how does mysq_query($query) act as both a boolean and a data container at the same time? What's happening "under the hood" during these steps? (yes, I am a n00b..., please be kind!)

    Read the article

  • Validate input parameters in VB?

    - by EdOxH
    Should I validate input parameters on all functions I create? Input isn't passed from a user, but from other routines as part of an automatic process. I use error handling. I'm not sure what more validating input could do for me. If the input isn't valid, that's pretty much the same thing as an error, isn't it?

    Read the article

  • [CakePHP] I am so confused. What should I write in the default.ctp

    - by kwokwai
    Hi all, I am learning cakePHP, everything seems alright except that I am very confused of how to make use of the default.ctp and what should be put inside the Elements folder. Here is the default.ctp file that I have been using since my very first lesson on learning cakePHP: (I copied from this URL http://book.cakephp.org/view/96/Layouts) <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title><?php echo $title_for_layout?></title> <link rel="shortcut icon" href="favicon.ico" type="image/x-icon"> <!-- Include external files and scripts here (See HTML helper for more info.) --> <?php echo $scripts_for_layout ?> </head> <body> <!-- If you'd like some sort of menu to show up on all of your views, include it here --> <div id="header"> <div id="menu">...</div> </div> <!-- Here's where I want my views to be displayed --> <?php echo $content_for_layout ?> <!-- Add a footer to each displayed page --> <div id="footer">...</div> </body> </html> But the problem is that the layout will take effect to all web pages that I have created. Let's see the case that I have recently encountered. In one of the .ctp files, I need to use JQuery function and I need to ass some and tags in the .ctp file. Here are the and tags I used: <Script language="javascript"> $(document).ready(function() { // some functions here }); </Script> <style type="text/css"> { #toppage{ width:800px; } But when I followed the default.ctp file, I noticed that these tags (i.e. and ) happened to appear below the tag. As far as I know, the and self-defined Javascript functions should be put inside the tag of the HTML instead. I have considered to add the and in the default.ctp file, but then these codes would appear in every web pages instead of just a particular web page. Please help.

    Read the article

  • How do you avoid an invalid search space in a genetic algorithm?

    - by Dave
    I am developing a GA for a school project and I've noticed that upon evaluating my functions for fitness, an individual is equivalent to its inverse. For example, the set (1, 1, -1, 1) is equivalent to (-1, -1, 1, -1). To shrink my search space and reach a solution more efficiently, how can I avoid my crossovers from searching in this second half of the search space?

    Read the article

  • need a project design tool

    - by santosh
    I am looking for simple and easy to use tools through which I can get project's visual picture of folder/file tree stucture , its classes, functions and objects, relations between classes and files.

    Read the article

  • Add text to every line in text file using PowerShell

    - by Joshua
    I'd like to add characters to the end of every line of text in a .txt document. #Define Variables $a = c:\foobar.txt $b = get-content $a #Define Functions function append-text { foreach-Object { add "*" } } #Process Code $b | append-text Something like that. Essentially, load a given text file, add a "*" the the end of every single line of text in that text file, save and close.

    Read the article

  • Prototype's update not working with IE

    - by xain
    Hi, I'm having problems updating a div's content in IE using .update; I also tried with innerHTML with no success. My script works fine with firefox and chrome, but I need to make it work with IE too (neither 7 nor 8 accept the functions). Any hints ? Thanks in advance.

    Read the article

  • Big, Thick Reference Books (PHP / MySQL / Unix) [closed]

    - by Josh K
    I'm looking for in-depth reference books / guides in PHP, MySQL, and Unix. I'm aware there other other questions pertaining to good books for short references of function names, or detailed beginner guides to these systems. I'm looking for something different. I want a book that I can either use as a quick but in-depth (decent write up, not a pocket reference guide) reference to common functions (JOINS, string manipulation, Regular Expressions, etc) while also providing a detailed inner workings explanation on the system itself.

    Read the article

  • Share your conky tips / scripts / .conkyrc

    - by Chad Birch
    I've just started tinkering with conky, and I'm hoping the StackOverflow crowd can share some of the cool things they've done with this tool. Scripts and .conkyrc files specifically geared towards developers would be especially good to see. Some good examples of developer-centric functions would be repository-monitors or heck, even something that monitors StackOverflow. Screenshots of what the functionality actually looks like would be appreciated as well.

    Read the article

  • how to access objects in run-time in qtp?

    - by Onnesh
    We have a function which accesses two types of controls like button and list box in standard windows app. The function uses only the control name as arguments, so there is no way qtp could understand what type of control it is. how to resolve this? Write 2 separate functions- 1 for button & another for list box?

    Read the article

  • On iPhone, what does EPERM (errno == 1) mean in reponse to send() of UDP data?

    - by Chris Markle
    We sending data over UDP from the iPhone, sometimes, but not always, in response to our first send() of UDP data, we are getting back a -1 return code and errno set to 1 (EPERM / operation not permitted). The EPERM result for send(), sendto() and sendmsg() is not documented in the man pages as a return result from those functions. Has anyone out there encountered this and might be able to shed some light on what this errno value means in this context?

    Read the article

< Previous Page | 153 154 155 156 157 158 159 160 161 162 163 164  | Next Page >