So I am writing an assignment to Detect prime numbers and it works by Asking for how many values you are going to enter, and then saying "Enter value 1: "
Then you would input and it would calculate via for loop, and that part is working. However to make my program more foolproof, I devised a way for the user to be unable to "Break" the program by inputting characters or float values. Here is the code for that:
while(!(cin >> num)){ //num is some type (char, float, int etc.)
cout << "That is not at valid input, please try again" << endl; //"Error Message"
cin.clear();
cin.ignore(10000, '
'); //Clear and reset cin
cout << "Enter value " << n << ": "; //Re-Prompt User for input
//n is whatever value the for loop is on
}
and this code works fine, I was just curious about how i would turn it into a function. Preferably wiht the name: ValidateInput(Param1, Param2);
The Parameters of the function preferably would be the variable youre inputting and the message you want to prompt. So somehow i wish to have it so for the above example it would look like:
ValidateInput(num, "Enter Value " << n << ": ");
But I don't know exactly how to label either parameter part because I want it to work for chars, ints, floats etc. And I don't know what I want it to return if anything either.
We have to ask the user to select either a Visa card type or Mastercard type. Then, we must ask the user to enter the 16 digit card number and determine if the card is valid or not using module 10. If the answer is zero then it is a valid Visa card and if the answer is zero the answer is a valid MasterCard. My problem is that the I have not separated the validation for MasterCard separate from visa.
Here is what I have so far:
#include <iostream> #include <iomanip> #include <string> using namespace std; int main() {
I am trying to create a custom ValidationAttribute in my c# .net code. I have done a lot of searching and have code that should be working but the IsValid method is not firing as far as I can tell.
Model code:
[Required(AllowEmptyStrings = false, ErrorMessage = "required")] //[Range(2014, 2100, ErrorMessage="Please enter a valid year.")] //[RegularExpression(@"^d{4}$", ErrorMessage = "Please enter a valid year.")] [ValidYear(ErrorMessage="Please enter one >= 2014")] [Display(Name = "Exp. Year")] public string expYear { get; set; }
And this is the class in that same model:
public class ValidYearAttribute : ValidationAttribute { protected override ValidationResult IsValid(object value, ValidationContext validationContext){ return new ValidationResult("Something went wrong"); } }
I need to create a main function with a one dimension dynamic array with float data type. The total number of array elements must be controlled by a user input from the keyboard. Test data is three different lengths 3,6,9 of the array. The lengths have to be set up at run time from users input. I understand how to create dynamic array but not where the user inputs the length of the array. How would I implement this?
Any way to create an "umbrella" type/class/struct of existing c++ types or windows types.
I want to address ~3 different structs with a single pointer and downcast but, they are not a part of the same hierarchy.
Is there a way that I could for example's sake, include a POINT and a RECT under some "umbrella" type so I can go like this:
// Working Variables //--------------------------------------------------------- Umbrella* pUmbType1(NULL); Umbrella* pUmbType2(NULL); POINT ptExamp = { 0 }; RECT egRect = { 0, 0, 0, 0 };
// Typecast POINT and RECT to umbrella pointer //--------------------------------------------------------- pUmbType1 = (Umbrella*)ptExamp; pUmbType2 = (Umbrella*)egRect;
I want to do this, so I don't have to duplicate code for each type.
I have a struct called Array and I'm to create a function to create a dynamic array that's fill with randomly generated integers from 0 to 50 (inclusive) and a function to destroy the array for freeing its memory. Below the code that I have written so far.
Code:
* Struct */ typedef struct {int *pArray; //the dynamic array int length; //the size of the dynamic array}Array; /* Function to create a dynamic array */ Array *initializeArray (int length) {int i; }
i need to create a new integer data type called BigInt to store a big big integer, which includes Dint(8 bytes) and Qint(16 bytes)
here is the hint/
typedef struct BigInt { Int data[2]; }
How can i "scanf" and "printf" them????
void ScanBigInt(const char *format, BigInt &x) if format is “%dd” -> input Dint, if format is “%qd”--> input Qint void PrintBigInt(const char *format, BigInt x)
What i'm trying to create is a simple State Manager for SFML! I created another class that inherits State.
#pragma once #include "state.h" class FirstState : public State { public: FirstState(); ~FirstState(); void handle_action(); void update(); void render(); };
So the question is this, each state that i have will inherit the State class. However, i wanted to perhaps add each state object into a vector array. But i'm not sure as to what data type it be? I have a state manager class that will contain the vector.
What i want to do is this, each game state will create an object that will inherit functions from the state.h class. I want to store them all in a vector array, but each object is clearly named different. My curiosity was wondering, since all those different states inherit the State.h class, can i simply create a State Object std::vector<State> *states; that will contain all those different state objects?
I have this int type function that returns a number. It returns the value 2 for now but later it will return more variety of values. How do I use the value it returned? I'm not sure of the proper syntax.
My g++ compiler is telling me that said printTest() is not part of the class. I have presented it in header class and implemented it in .cpp class but still keep getting the error. Compile and compile error -
blackjack > g++ -Wextra -pedantic -std=c++11 Deck.h Deck.cpp test.cpp ; test.cpp: In function ‘int main()’: test.cpp:6:6: error: request for member ‘printTest’ in ‘test’, which is of non-class type ‘Deck()’ test.printTest();
The function im having problems with takes an array where each element is an array of unsigned chars i.e. octals representing a bitmap of one of 95 ASCII code characters and searches through this two dimensional array looking for a match for a predetermined of array of unsigned chars i.e. the bitmap of a predetermined char. If we find the char the function outputs the index in the two-dimensional array where each elem. is an array of octals ELSE it return -1 i.e. when the char is not found.
I have 2 files, one .cpp, the other .h. There is a function named find_char. See INPUT and OUTPUT on line 48 in .cpp file.
The exception im getting is: font2.cpp:23:45:error: invalid conversion from unsigned char to unsigned char(*)[5]
The input type specified for my function prototype corresponding to find_char. If I put just unsigned char it doesn't fix the problem because it's an array parameter i.e. like a call by reference. I've lead myself to believe that the array variable contains a pointer to the first value in the array and so I've made function prototypes that work with a T* i.e. a pointer to type T. Making the function prototype argument unsigned char* i.e. a pointer to unsigned char simply gives me the exception: "invalid conversion from unsigned char to unsigned char*". When I have the argument be 'unsigned char' I get undefined reference to find_char(unsigned char). URL.....
#include<iostream> #include<string> using namespace std; int bin2dec(const string binarystring); // Declaration of bin2dec prototype with one string parameter int main() { cout << "Enter Q to terminate program.
[Code] .....
Right now the code is in the form of a 'const string binarystring' and were supposed to be able to use 'const char binarystring[]' and for some reason whenever i try to switch it i run into problems when referencing the main function to the int bin2dec(...) function.
I wanted to know if theres a simple way to switch the prototype to an array type of function with [] without changing the entire code.
I need to create the following brain damaging abomination:
I need a function pointer type to a function that has an argument of the same function pointer type and returns the same function pointer type.
The purpose is to enable a type of subroutine threading scheme for a small application specific scripting language. The question could just as well have been posted to the C forum.
This syntax works, but Payload is a generic type which I can coerce into the right pointer type via a cast. This is ugly IMHO. I could also hide it as a pointer in the FlipState class since I've forward declared this.
But this is an extra indirection in a performance critical part of the code, and also ugly.
Code: class FlipState ; typedef PayLoad (*FuncPtr) (FlipState *fs, PayLoad P) ; This syntax blows chunks using gcc on the other hand. Code: class FlipState ; typedef FuncPtr (*FuncPtr) (FlipState *fs, FuncPtr P) ;
[Code] .....
This is hardly surprising. The compiler could not possibly understand what I was defining in the typedef. I think what I need is some kind of way to forward declare a function pointer type and then redefine it properly.
Is such a think even possible or am I just SOL? This one is mind boggling. We know how to do this with classes or other complex data types, but the syntax eludes me for both C++ and C.
Variably modified types are subject to certain restrictions , just as variable-length arrays are. The most important restriction is that the declaration of a variably modified type must be inside the body of a function or in a function prototype.
Code: void f(int m , int n) { int a[m][n] , (*p)[n]; p=a; //.... }
What does it mean? That we can't declare such a pointer as a global variable?
I am having problems with my function definition of a function that should return a structure value.
This is the error I get compute.cpp(9): error C2146: syntax error : missing ';' before identifier 's_advertisebus'
The error is on the line where I start my function definition typing my function type as a structure. A long time ago in c the keyword struct is used with the structure type like struct s_advertisebus s_readadbus(). I tried it both ways but I got errors.
// struct.h #ifndef STRUCT_H #define STRUCT_H
struct s_advertisebus { int nnumberofads; float fpercentused;
I have always written like a>='0'&&a<='9'&&a>='a'&&a<='z' in loops etc, but no more. Basically add whatever you want to condition, and if you want point a to point b just separate them with a '-' sign. Simply
"Write a declaration for a function that takes two int parameters and returns an int, and declare a vector whose elements have this function pointer type."
