Constant

If you have a static variable that never changes and you want that nobody overrides your variable, use the const keyword by declaration. It makes the variable unchangable (constsant).

For example:

python
const double x = 42;

The variable x will always be 42 and nobody can change it. The following code would cause an error:

python
9
1
2
const int x = 10;
x = 15;

You should declare variables as constants if you are sure that they will probably never change:

python
9
1
2
const int monthPerYear = 12;
const char firstAlphabetLetter = 'A';