If you just want to pass a std::string to a function that needs const char* you can use std::string str; const char * c = str.c_str(); If you want to get a writable copy, like char *, you can do that with this: std::string str; char * writable = new char[str.size() + 1]; std::copy(str.begin(), str.end(), … Read more
When you add the const keyword to a method the this pointer will essentially become a pointer to const object, and you cannot therefore change any member data. (Unless you use mutable, more on that later). The const keyword is part of the functions signature which means that you can implement two similar methods, one … Read more
It depends on what you need the value for. You (and everyone else so far) omitted the third alternative: static const int var = 5; #define var 5 enum { var = 5 }; Ignoring issues about the choice of name, then: If you need to pass a pointer around, you must use (1). Since … Read more
department is meant to be a string (to be used here as array key). Strings in PHP must be enclosed in quotes. In the days of the long past PHP was lax about using quotes for single-word strings but these days are long gone. Therefore, it must be ‘department’ or “department”. The same goes for … Read more
From this Visual C++ blog article about rvalue references: … C++ doesn’t want you to accidentally modify temporaries, but directly calling a non-const member function on a modifiable rvalue is explicit, so it’s allowed … Basically, you shouldn’t try to modify temporaries for the very reason that they are temporary objects and will die any … Read more
@thefourtheye is correct in saying that these variables cannot be accessed before they are declared. However, it’s a bit more complicated than that. Are variables declared with let or const not hoisted? What is really going on here? All declarations (var, let, const, function, function*, class) are “hoisted” in JavaScript. This means that if a … Read more
Read it backwards (as driven by Clockwise/Spiral Rule): int* – pointer to int int const * – pointer to const int int * const – const pointer to int int const * const – const pointer to const int Now the first const can be on either side of the type so: const int * … Read more
The difference here is that char *s = “Hello world”; will place “Hello world” in the read-only parts of the memory, and making s a pointer to that makes any writing operation on this memory illegal. While doing: char s[] = “Hello world”; puts the literal string in read-only memory and copies the string to … Read more
The code given looks OK, but if you want the sum without including the last number, as is generally the case you should change the for loop like this for(; index < endno; index ++)
First, use camelCase for naming in Swift. lowerCamelCase for constants/variables/functions and UpperCamelCase for types (classes, …) MAX_RADIUS_IN_MILE -> maxRadiusInMile Now to your problem. Error is clear, you have constant of type Double (if you don’t specify type of decimal number, compiler give it type Double), but assigning maximumValue requires type Float. What now? One solution … Read more