Is it worth adding constants to a class?

Question

OOP

What do you think, is it right to make definitions of constants in a class if these constants are used only inside the class. Or is it considered bad programming style?
Example:

class SomeClass {
    private readonly CONST_FOR_CLASS_ONLY = 'value of constant';

    methodOfClass() {
      // использование this.CONST_FOR_CLASS_ONLY
    }
  }

Answer 1

Constants in the class are normal practice, but they should be static, there is nothing to duplicate them in each instance.