Can you have a const reference C++?

Just like it’s possible to declare a pointer to a const value, it’s also possible to declare a reference to a const value. This is done by declaring a reference using the const keyword.

Is reference a const pointer?

Const pointers can be NULL. A reference does not have its own address whereas a pointer does. The address of a reference is the actual object’s address. A pointer has its own address and it holds as its value the address of the value it points to.

Can references be const?

References are inherently const , that is you can’t change what they refer to. There are ‘ const references’ which are really ‘references to const ‘, that is you can’t change the value of the object they refer to. They are declared const int& or int const& rather than int& const though.

What does const reference mean in C++?

if you are using const reference, you pass it by reference and the original data is not copied. in both cases, the original data cannot be modified from inside the function.

How do you declare a reference in C++?

References in C++ When a variable is declared as a reference, it becomes an alternative name for an existing variable. A variable can be declared as a reference by putting ‘&’ in the declaration.

How do you initialize a reference variable in C++?

References are initialized in the following situations:

1. 1) When a named lvalue reference variable is declared with an initializer.
2. 2) When a named rvalue reference variable is declared with an initializer.
3. 3) In a function call expression, when the function parameter has reference type.

How do you use a const pointer?

We declare a constant pointer. First, we assign the address of variable ‘a’ to the pointer ‘ptr’. Then, we assign the address of variable ‘b’ to the pointer ‘ptr’. Lastly, we try to print the value of the variable pointed by the ‘ptr’.

Can I modify a const reference?

But const (int&) is a reference int& that is const , meaning that the reference itself cannot be modified.

What is reference in C++ with example?

Advertisements. A reference variable is an alias, that is, another name for an already existing variable. Once a reference is initialized with a variable, either the variable name or the reference name may be used to refer to the variable.

Can you reassign a reference C++?

As for your second question, references cannot be reassigned once bound to an object. If you need to have a reference that can change its referent, you should be using a pointer instead.

How to use const with reference to a pointer?

In Example 1, the ptr_ref is a const reference to a pointer to int, and we are trying to change the value of ptr_ref. So the compiler throws a Compile time error, as we are trying to modify a constant value.

How to declare constant pointer in C-codeforwin?

Syntax to declare constant pointer * const = ; Note: You must initialize a constant pointer at the time of its declaration. Example to declare constant pointer int num; int * const constant_pointer = &num // Constant pointer to num. Note: We use const keyword to declare a constant pointer.

Which is a pointer to a constant Char?

char* const is a pointer to a char, where you can change the char, but you can’t make the pointer point to a different char. const char* const is a constant pointer to a constant char, i.e. you can change neither where the pointer points nor the value of the pointee.

Can a reference to a const int be changed?

As a result, the value of int changed to 100. Reference to a Const Pointer is a reference to a constant pointer. Here again we get compile time error. This is because here the compiler says to declare ptr_ref as reference to pointer to const int. So we are not allowed to change the value of i.