C++ :: Initializing Array Of String Type In A Class
Apr 28, 2013
I want to use this array as part of my class. I have tried several different angles trying to get it to work but with out success. I have been checking to see if it works by simply using "cout << dayName[3];" It is printing nothing at all. What is the proper way to initialize this array of strings?
First I tried this:
const string dayName[] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
A have two classes, one inheriting the other, and the parent class being abstract (I plan on adding more child classes in the future). For reasons I won't bother mentioning, I'm making use of an STL container as a way for me to access all of the child objects in the heap. I've done so by making use of a map, with key type int and value type being a pointer to the parent class:
//PARENT.H class Parent { protected: static int n; static std::map<int, Parent*> map; public: virtual void pureVirtual() = 0;
[code]....
The Problem:In line 5 of Parent.cpp, initializing the value of the element to new Child won't work, as according to the compiler, the Child class hasn't been declared yet, and including Child.h into the Parent.h only opens an even bigger can of worms.I also can't initialize it as new Parent, seeing as the parent class is an abstract one.
The Question:Is there a way I can initialize the static map properly. Making the Parent class abstract is not an option.
In one of my programs I have a 3x3 array of string that I use to display the outcome to rock, paper, scissors, and another 1x3 used for a number guessing game. I have the arrays declared in the header file as follows:
//Games.cpp string rpsOutcome[3][3] { //row 1 { "Both of you picked rock, you tied. Try again", "You picked rock, the computer picked paper, you lose",
[code]....
From what I've read, Im pretty sure thats how your supposed to initialize multidimensional arrays (using the nested braces), but when I build the project, I get the following error:
I have defined my own class, Queue, which inherits from my own class, LinkedList. I have been using templates to allow Queues to be of int, string, etc types.
But now I want to be able to store objects in my Queue type. And so the problem I have is that in my LinkedList class, I have two instances where I initialize an instance of my generic type T to 0.
For instance, the removeFirst() method starts like this:
template <typename T> T LinkedList<T>::removeFirst() { T a = 0;
And so the compiler complains that it can't convert from int to [in this case] Command&.
Let's say I have a Car object , and it contains inner Engine object.
Code: struct Car{ Engine mEngine; };
In order to initialize the engine object NOT by the default constructor (if it has any) , we use initialization semantics:
Code: Car::Car: mEngin(arg1,arg2,...) { other stuff here }
Now it gets tricky: Let's say a Car objects has 10 inner objects, each object has about 5 variables in it . Car is a base class for , e.g. , Toyota class. you don't want the Car class to have a constructor with 50 arguments. Can the inner objects of Car be initialized from the base class , e.g. Toyota?
Code: class Toyota: Car(...), mEngine(...), mGear(..) { ... };
The other options are: 1) like said , create a Car constructor which gets 50 arguments, then initialize Car as whole from Toyota - the code becomes less readable and less intuitive 2) Car constructor which get built-objects as arguments and initialize the inner objects with copy constructor . the code gets more readable but then you create many excess objects .
I have a class MySeqBuildBlockModule that I am inheriting from: public SeqBuildBlock. Other than constructor and destructor, this class MySeqBuildBlockModule has a method: prep.
class MySeqBuildBlockModule: public SeqBuildBlock { friend class SeqBuildBlockIRns; public: MySeqBuildBlockModule (SBBList* pSBBList0, long TI1_In, long TI2_In)// more arguements in this constructor of derived class : SeqBuildBlock (pSBBList0)
[code]....
I would have like to intiantiate an object "myIRns_3" of a class defined in third party library
SeqBuildBlockIRns myIRns_3(pSBBList2);
and would like to access it from the prep function as:
I tried to instantiate following in either private section or in constructor; but w/o any success:
SeqBuildBlockIRns myIRns_3(pSBBList2);
ERRORS encountered:
When I tried to do it inside the constructor, I get the following errors:
MySBBModule.h(113) : error C2065: 'myIRns_3' : undeclared identifier MySBBModule.h(113) : error C2228: left of '.getEnergyPerRequest' must have class/struct/union type MySBBModule.h(116) : error C2065: 'pSBBList' : undeclared identifier MySBBModule.h(116) : error C2227: left of '->prepSBBAll' must point to class/struct/union
When I tried to do it in private section, I get the following errors:
MySBBModule.h(106) : error C2061: syntax error : identifier 'pSBBList2' MySBBModule.h(113) : error C2228: left of '.getEnergyPerRequest' must have class/struct/union type MySBBModule.h(116) : error C2065: 'pSBBList' : undeclared identifier MySBBModule.h(116) : error C2227: left of '->prepSBBAll' must point to class/struct/union
I am having trouble with the array pointer and with the variables. I don't seem to have the pointer set up because the additional times the array is called it is empty. Also, if I don't use integers the program drops through. where I am going wrong?
Question is in the code
/* NumClass Main.cpp ******************************************************************************************* * * Design a class that has an array of floating point numbers. The constructor should accept an integer argument and dynamically allocate the array to hold that many numbers. The destructor should free the memory held by the array. In addition, there should be member functions to perform the following operations: * **Store a number in any element in of the array
I am working on a homework assignment and have most of the program working, but when I try to compile it keeps telling me to initialize the coin variables in each class. However, they are supposed to be added then removed so I don't want to set them back to zero.
Rewrite the Purse program given in Page 35 with functions to perform insert and remove operations. The function insert (int p, int n, int d, int q) will initialize pennies, nickels, dimes and quarters. The function dollars() will return the dollars. The function remove (int p, int n, int d, int q) will subtract pennies, nickels, dimes and quarters. The function display() returns a new String to print the content of the purse with remaining pennies, nickels, dimes and quarters.
Code: usingnamespace std; int insert_money (int *p, int *n, int *d, int *q); int remove_money (int *p, int *n, int *d, int *q); int dollars(); int main()
I have an assignment where I need to read in a phone number into any array and I can't use the string data type. Assuming I need to use the getline function, how do I do this? I'm guessing it's with the cstring or .c_str() functions? I don't know.
I've created a function where you can choose any bounds for an array based list (positive or negative, as long as the first position is smaller than the last position). However for some reason when I call the print() function in my application program it doesn't do anything. My print function is technically correct (I still have work to do on the output) but I can't figure out why it wont show anything at all. Below is my header, implementation, and main program files, along with results from running the program.
I've written this class and struct to create a singly linked list. The data is stored in the binary file which I've opened and read. I'm trying to load said data into a class type array. The errors I'm getting are "incompatible types in assignment of 'StatehoodInfo' to char[3]" Lines 130-134 is what I was working on.
The problem with that is that string.data isn't considered const during the initialization of the String struct so the compiler throws an error. It doesn't feel very elegant to do it like this either way.
Is there an elegant solution to this problem? I would like to avoid making a copy of the string literal.
class Base { char * ptr; public: Base(){} Base(char * str)
[code].....
Obj1 is a derived class object where base class char pointer is initialized with "singh" and derived class char pointer is initilized with "sunil". I want to create Obj2 out of Obj1. Separate memory should be created for Obj2 char pointer (base part and derived part as well) and that should be initialized with the strings contained in Obj1.
Here the problem is: Derived class part can be initialized with copy constructor. How to initialize the base class char poniter of Obj2 with the base class part of Obj1. char pointers in both the classes are private.
I tried using initializer list but could not succeed.
I am making a tictactoe program that requires me to have a 3 by 3 two dimensional array of integers, in which the constructor should initialize the empty board to all zeroes. The program complies, but it keeps outputting garbage values and i'm not entirely sure why, My print function isn't complete yet, since I want to print out the array in a tic tac toe format, but i'm more concerned with why it's printing garbage values, here is my code:
I am going to be using a boolean variable to mark whether or not a specific field has had data entered into it. I figure the best way to do that is to initialize all the elements of the structures to 0. However, with strings and with the nested structure, I'm not sure how to do this.
Want to initialize a local one dimensional array. How can I do the same without a loop?
Found from some links that int iArrayValue[25]={0}; will initialize all the elements to ZERO. Is it? If yes then can we write below code to initialize the elements to a non-ZERO value?
int iArrayValue[25]={4};
Do we have some other way to initialize an array to a non-ZERO value? Memset can initialize the element to ZERO.
I am making a tic tac toe program in which they are asking me to have a 3x3 2 dimensional array of integers and have the constructor initialize the empty board to all zeros. They also want me to place a 1 or 2 in each empty board space denoting the place where player 1 or player 2 would move The problem I'm having is, my code initializes the board to all zeros for each element of the array, and prints it out just fine, but I can't figure out how to re-initialize the values in the array to show where each player moves on the board... I was thinking about having a default constructor that has each value set to zero, and then use a setGame function that can change the values on the board to one or two depending on where the player moves....but I don't know if that's possible.....
I'm learning OpenGL using the C API and some of the functions' argument types have proven a bit challenging to me.
One example is the function Code: glShaderSource(GLuint shader, GLsizei count, GLchar const** string, GLint const* length); It resides in foo() which receives a vector "data" from elsewhere Code: void foo(std::vector<std::pair<GLenum, GLchar const*>> const& data); To pass the pair's second element to glShaderSource's third argument, I do the following:
1. Can I initialize a char const** via initialization list, the way I do a char const*?
Code:
// this works std::vector<std::pair<GLenum, GLchar const*>> const shader_sources = { {GL_VERTEX_SHADER, "sourcecode"}, {GL_FRAGMENT_SHADER, "sourcecode"} }; // but is this possible?
