when to use ??= operator? From MSDN: The null-coalescing assignment operator ??= assigns the value of its right-hand operand to its left-hand operand only if the left-hand operand evaluates to null. For example, int? a = null; … a ??= 5; //Here a is null, so assign 5 to a int b = a ?? … Read more
Just to show you current C++ (C++20) works a bit different then wat most (older) C++ material teaches you. #include <algorithm> #include <iostream> #include <string> #include <ranges> bool is_not_four(const char digit) { return digit != ‘4’; } int main() { // such a big number iwll not fit in any of the integer types // … Read more
Why doesn’t this code use the C++ power function directly? Can someone help me with the power function in this code? [closed] solved Why doesn’t this code use the C++ power function directly? Can someone help me with the power function in this code? [closed]
int array[size] declares an array of size elements. Outside of a declaration, array[size] access element size in array. It does not resize the array. If you do something like that without changing the value of size, it actually tries to access the element after the last element in the array; not a good idea. In … Read more
Look at this: “How to: Get Information About Files, Folders, and Drives (C# Programming Guide)” http://msdn.microsoft.com/en-us/library/6yk7a1b0.aspx For example: // Get the files in the directory and print out some information about them. System.IO.FileInfo[] fileNames = dirInfo.GetFiles(“*.*”); foreach (System.IO.FileInfo fi in fileNames) { Console.WriteLine(“{0}: {1}: {2}”, fi.Name, fi.LastAccessTime, fi.Length); } You can change the Console.WriteLine to … Read more
Use the following code: if(strcmp(name,empName)==0) { … } Note that there must be no quotation marks around empName to compare its contents. 0 solved Strcmp() function not working properly [closed]
void findErrors(int lineIndex){ char *line; strcpy(line, lines[lineIndex]); //^ this is undefined behaviour. At that point line is not initialized and strcopying something to a non initialized pointer results in undefined behaviour, usually a segfault. But if by chance line points to some valid memory, the program may not crash and it may look as if … Read more
List test = NULL; one(&test); test is a pointer to struct node. We pass the address of that pointer to one, allowing one to change test (letting it return a new pointer is a cleaner way to do this). one then executes this: two(&self); two is now being passed the address of the address of … Read more
with your “warning” you also get a string number, where “warning” appears. please give the string where an error appears I did not see at first time your warnings just replace the -1 to NULL or replace -1 to (void *)-1 course standard should be written to NULL, but if you really want, you can … Read more
Header files normally only contains prototype declarations of methods, just to satisfy initial compiler checks. The implementation files are already compiled to binary forms and distributed as library files. They are linked to your program during the linking process. If you have studied C, you will remember that you used to add a prototype declaration … Read more
v is a pointer, and it looks like VECTOR expects its argument to be a value. So change VECTOR(v) to VECTOR(*v). 1 solved error: request for member ‘stor_begin’ in ‘v’, which is of non-class type ‘igraph_vector_t*’
You can use public bool IsAlpha(string strToCheck) { Regex objAlphaPattern=new Regex(“[^a-zA-Z]”); return !objAlphaPattern.IsMatch(strToCheck); } Regards solved Validate input string [closed]
Instead of: class MyClass { private int _value; public MyClass() { _value = OtherClass.StaticInt; } } Favour: class MyClass { private int _value; public MyClass(int valueForConstruction) { _value = valueForConstruction; } } Decouples MyClass from OtherClass, even if you do this: MyClass c = new MyClass(OtherClass.StaticInt); 2 solved Access static property in another class’s non-static … Read more
If you can’t use std::map, you can associate the word with the frequency: struct Info { std::string word; int frequency; }; //… std::vector<Info> database; //… std::string word; while (std::cin >> word) { // Find the word: const size_t length = database.size(); for (unsigned int i = 0; i < length; ++i) { if (database[i].word == … Read more
You can generate random numbers by using the built in Random class, and use the array function Contains to check if the number generated is already in the array. In my example below I generate a new numbers until I find one that isn’t in the array yet, then add it. Random rand = new … Read more