I have a class that I'm going to use to store a category. Right now there are seven options, but there is the potential for a whole lot more in the future. So I started off by storing an integer as the private member. I then used static constants to define the numeric values to represent each category, then a set of static constant strings that corresponds to those numbers in case I need their actual names. Finally I set up some static functions to convert between the integer value and the string, and vice versa.
I'm not sure if this is the best way to go about this. For one it makes the categories names and designations unchangeable. I thought that storing them in a file would be a better option, but then i needed a container that is the equivalent of a constant.
I thought of defining a class to contain an int and the associated string. It would be designed so that it can only be initialized with both items. Then provide no functionality to change the contents. So I've basically created my own constant.
When using an iterator with a std container (list / vector etc) sometimes it's possible to modify the container (e.g. delete an item) yet still carry on using the iterator - whereas in other cases, modifying the container immediately invalidates any open iterators on it. Is there an easy way to know which containers fall into which category? (or does it vary from one compiler to another?)
Given a product category and subcategory representation:
a. Come up with a tree data structure to minimally (in terms of storage) represent this b. Write a program to convert the given representation (shown in example below) to this c. Write a function to output the tree structure in a nice human readable format
Note: a. There can be any number of levels of depth b. Rows may be repeated in input, but need to feature only once in the final tree.
Example category list (read this input from a file):
decalration won't allocate storage, while definition will. This is a test program:
#include <iostream> using namespace std; extern int ei; int i;
[Code].....
Others are all fine in this program except ei. compiler error: undefined reference to ei.
I understand ei is only declared so there is no memory address, but when I do ei=1, then ei completed it's definition, why still cannot use pei to get it's address?
I made a program and when I try to use the main driver to instantiate everything it says invalid storage class for a function. All of my code is in 4 separate files i'm just trying to get it to run now.
I am porting code from windows using visual studio to mac with xcode.
Quite a lot of issue have a appeared, which is no surprise, one warning that keeps on appearing is Explicit Specialiszation cannot have a storage class:
So the RPG I have been making is based on this tutorial URL.....I don't entirely understand how the Item storage system is supposed to work. It looks like the array shown is for one item but, there are 3 lines of code that correlate. The author says that this is a repeatable bit of code for each item so.... i'm just completely lost. The player will have two or three to start and there are 4 battle/health items and one key ....
where to start and how it should be structured. how I should go about writing this program, like should i make functions, pointers, etc. And to display the menu, is it easiest to just use printf statements or is there something more efficient.
#include <iostream> class Hello { public: void Test() {
[Code].....
As i know a non-constant member function cant be called inside a constant member function but how the above code has been compiled successfully and giving the expected result .
I have never seen anyone pass by const copy and there probably is a reason. I know that the compiler ignores top level const-ness of function arguments. There are functions which take arguments without manipulating those arguments return the result, for example the C Standard Library funcion double sqrt (double x). The function shouldn't modify it's argument, but it can since the argument isn't const.Take these two functions for example:
double square_root_1(double arg) { arg = 7; // we won't get the desired results return arg * arg;
[code]....
So isn't it better to pass by const copy to make sure that you (or someone else) don't by accident modify the argument? The only disadvantage I see is that it makes the code too verbose.
