What is the difference between #define and const in c++

Question

#define vs const in c++

Answer 1

#define: the compiler replaces the part of the program it uses it, therefore it is more faster:

#define x 10
printf("%d", x);
gets replaced to:
printf("%d", 10);

constant values are normal values that can't be changed.

Answer 2

I did.

Answer 3

Then I don't think I can help you anymore

Answer 4

#define is a preprocessor directive, whatever expression you set in #define will be used to replace every occurrence of the identifier.

Syntax:
#define <identifier> <expression>

Before compilation begins, every occurrence of <identifier> in your code shall be replaced by the <expression> it represents. Note that preprocessor directive doesn't need semicolon at end.

const is a qualifier, it adds an attribute to an identifier that marks the identifier as read-only, meaning an attempt to modify its value (data) will result in failure and warning or possibly error.

Syntax:
const <type> <identifier> <value>

P.S. Please lookup the net for more descriptive and clear definition of preprocessor directive and const qualifier, my attempt to answer may be mistaken or inappropriate from lack of in-depth knowledge.

Answer 5

Airree sorry I don't think you answered my question the question is the difference between #define and const

Answer 6

Then I don't understand