What is "mutable" keyword?

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What is "mutable" keyword?..

Answer / roshanpr

mutable key word is used when u want to make any member
variable of a const object modifyable.

Basically when u make a object constant u cannot modify its
data members. But during the declaration of the class if a
data member is declared as mutable it can changed.

Class my
{

mutable int age;

public:

my(){age=0;}
void plusplus(int b)const
{
age+=b;
}
};

int main()
{
const my obj;
obj.plusplus(40);
}

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What is "mutable" keyword?..

Answer / shakti singh khinchi

Mutable keyword is used to modify a data member of an object
which has declared as constant. for example:

class XYZ
{
public:
int i;
mutable int cc;
public:
XYZ();
};

int main()
{
const XYZ obj;
obj.cc = 100; // modify obj object's member "cc" which has
been declared as mutable.
}