Throughout this lesson, we’ve discussed the different ways we can manipulate a variable; however, what do we do with a variable that should never change its value?
For example, the year we were born will always stay the same. There’s no way we can change that information. A value like this in our code should be unchangeable.
To declare a variable with a value that cannot be manipulated, we need to use the
final keyword. To use the
final keyword, prepend
final to a variable declaration like so:
final int yearBorn = 1968;
When we declare a variable using
final, the value cannot be changed; any attempts at doing so will cause an error to occur:
error: cannot assign a value to final variable yearBorn
Create an unchangeable
double variable called
pi and set its value to
Print the value of
On a new line, try to change the value of
What happens when the program is run?