devxlogo

Meaning of const as prefix and suffix of function

Meaning of const as prefix and suffix of function

Question:
What is the purpose of placing a const at the beginning and end of a function declaration with a de-reference to the function? Are there memory leak implications?

For example:

 const DateTime &dataTime() const
where:
 DateTime is the type of the function        dataTime is the function name

Answer:
Consider:

int const i = 10; 
This declares i to have a type-constant integer, which means that the value of i cannot be modified once it has beeninitialized. Note that this is the same as saying:
const int i = 10;
The rule for this is: const modifies type of what is written before it, except when it is the first word in a declaration, in which case it always modifies the type declarator after it.

So, for uniformity, I like to write the former way.

When the const modifier is applied to a member function, the member function shall not change the state ofthe object it called for. For example:

class Foo {public:   int bar () const;private:   int i;};int Foo::bar () const{   i = 10; // not allowed; const method cannot change state.}
devxblackblue

About Our Editorial Process

At DevX, we’re dedicated to tech entrepreneurship. Our team closely follows industry shifts, new products, AI breakthroughs, technology trends, and funding announcements. Articles undergo thorough editing to ensure accuracy and clarity, reflecting DevX’s style and supporting entrepreneurs in the tech sphere.

See our full editorial policy.

About Our Journalist