Const keyword
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In C++, the const keyword is used to indicate that a variable, pointer, reference, or function cannot be modified.

When used with a variable, const makes the variable read-only, meaning that its value cannot be changed after it has been initialized. For example:

const int x = 5;
x = 6; // Error: assignment of read-only variable 'x'

When used with a pointer, const indicates that the value pointed to by the pointer cannot be modified, but the pointer itself can be changed to point to a different memory location. This is indicated by const appearing to the right of the *. For example:

int x = 5;
const int* ptr = &x;
*ptr = 6; // Error: assignment of read-only location '*ptr'
ptr = nullptr; // ok, changes the value of ptr to null

When used with a pointer, const appearing to the left of the * indicates that the pointer itself is constant, but the value it points to can be changed. For example:

int x = 5;
int y = 10;
int* const ptr = &x;
*ptr = 6; // ok, changes the value of x
ptr = &y; // Error: cannot assign to variable 'ptr' with const-qualified type 'int *const'

When used with a reference, const indicates that the reference cannot be used to modify the object it refers to. For example:

int x = 5;
const int& ref = x;
ref = 6; // Error: assignment of read-only reference 'ref'

const can also be used with member functions to indicate that the function does not modify the object it is called on. This can be useful for improving code safety and preventing accidental modifications to objects.

Here's an example:

class MyClass {
public:
  void foo() const {
    // This function does not modify the object
  }
};

In this example, foo() is a const member function of the MyClass class. This means that the function cannot modify any non-mutable data members of the MyClass object it is called on.
but there is a another way to get passed this imagine we have variable that we really want to change in a const method what should we do? we should make it mutable which means it should be changeable.

Overall, the const keyword is a useful tool for making code safer and more maintainable by indicating that certain variables and functions cannot be modified.

if you have code like int* a,b this means a is a pointer but b is still and integer so to make this correct we do this instead int* a,*b.

Overall, the const keyword is a powerful tool for making code safer and more maintainable by indicating that certain variables, pointers, references, and functions cannot be modified.

Const keyword...

Const keyword
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