安裝中文字典英文字典辭典工具!
安裝中文字典英文字典辭典工具!
|
- constants - What does const mean in C++? - Stack Overflow
int const* is a [non-const] pointer to a const int int const* const is a const pointer to a const int For whatever unfortunate accident in history, however, it was found reasonable to also allow the top-level const to be written on the left, i e , const int and int const are absolutely equivalent
- What is the difference between const int*, const int * const, and int . . .
const int *p;: When p is dereferenced with *, the expression is of type const int Therefore, p is a pointer to const int int *const p;: p is const If this constant expression is dereferenced with *, the expression is of type int Therefore, p is a const pointer to int const int *const p;: p is const
- What is the difference between const and const {} in JavaScript?
const email = obj email; const title = obj title; This is old school now We can use ES6 destructuring assignment, i e , if our object contains 20 fields in the obj object, then we just have to write names of those fields which we want to use like this:
- class - Why put const (. . . ) in C++ - Stack Overflow
const is only useful to enforce correctness, ie tell the compiler that if the developer directly modifies the object through the const reference, he is to be told off – spectras Commented Jun 28, 2017 at 7:03
- What is a const member function? - Stack Overflow
The method bar() is non-const and can only be accessed from non-const values void func1(const foobar fb1, foobar fb2) { const char* v1 = fb1 bar(); won't compile const char* v2 = fb2 bar(); works } The idea behind const though is to mark methods which will not alter the internal state of the class This is a powerful concept but is not
- c++ - What does `const T* const` mean? - Stack Overflow
This is a const pointer-to-const T So if T was an int, then array is a pointer to an int that is const in two ways: pointer-to-const: the value that the pointer is pointing to cannot be changed (or pointing to const int) const pointer: the memory address stored in the pointer cannot change This is also the same as T const * const array
- c++ - `const char - Stack Overflow
const char * Pointer to a `char` that is constant, it can't be changed const char * const A const pointer to const data In both forms, the pointer is pointing to constant or read-only data In the second form, the pointer cannot be changed; the pointer will always point to the same place
- Why can we use `std::move` on a `const` object? - Stack Overflow
The reason we have const keyword in the language is that we want the compiler to prevent any change to an object defined to be const Given the example in Scott Meyers' book: class Annotation { public: explicit Annotation(const std::string text) : value(std::move(text)) "move" text into value; this code { … } doesn't do what it seems to!
|
|
|