C++ Constants
Constants
When you do not want others (or yourself) to change existing variable values, use the const
keyword (this will declare the variable as "constant", which means unchangeable and read-only):
Example
const int myNum = 15; // myNum will always be 15
myNum = 10; // error: assignment of read-only variable 'myNum'
Try it Yourself »
You should always declare the variable as constant when you have values that are unlikely to change:
Notes On Constants
When you declare a constant variable, it must be assigned with a value:
Example
Like this:
const int minutesPerHour = 60;
This, however, will not work:
const int minutesPerHour;
minutesPerHour = 60; // error
Try it Yourself »