literals
Because these are the types used to declare variables and so these can be declared as constants.
In this program, we are finding the area of the circle by using concern formula.
We cannot modify a constant integer value.
The const will declare with a specific type values and #define is used to declare user definied constants.
They end with a semicolon
The first one refers to a variable whose identifier is x and the second one refers to the character constant x
It can turn this as wide character instead of narrow characters.
Because the const is used to declare non-changable values only.
