C++ “const” keyword explanation

Question

When reading tutorials and code written in C++, I often stumble over the const keyword.

I see that it is used like the following:

const          


        

Answer 1

Before a variable identifier, const indicates that the variable can be initialized and thereafter not modified.

After a class method name, const indicates that the method will not modify the observable state of the class. The mutable keyword allows internal data to be modified.

Before a pointer or reference variable, const indicates that the identifier will not be used to modify the referenced data, though it may be changed by other means.

const int *pInt = &x;

Const can also be used to indicate that the pointer itself cannot be modified:

int * const pInt = &x;