Читать книгу Excel 2019 Power Programming with VBA - Michael Alexander, Dick Kusleika - Страница 157

A variable's value may change while a procedure is executing (that's why it's called a variable). Sometimes, you need to refer to a named value or string that never changes: a constant.

Using constants throughout your code in place of hard-coded values or strings is an excellent programming practice. For example, if your procedure needs to refer to a specific value (such as an interest rate) several times, it's better to declare the value as a constant and use the constant's name rather than its value in your expressions. Not only does this technique make your code more readable, it also makes it easier to change should the need arise—you have to change only one instruction rather than several.