Why use constants?

Question

Is there a benifit for using a constant over using the other variable types?

Answer 1

They also can be used for set up. For example, I have the default speed of a foe (in a spaceship game, it will not change when the project will be finished). I use this value a lot in my code. If I want to change the value (to try with quicker foes), I'll just have to change the constant instead of changing every where I used it.
So, why not using a variable ? For the same reasons that was already told by @aklex : optimisation.

Answer 2

It also lets the compiler know that the object/variable will not change, which can open up more optimizations made by the compiler

Answer 3

Constants are for making sure that if you intend to create a value that cannot be changed, then you can know that a constant will never change and therefore is safer to use. This is how you can avoid debugging headaches down the line.

Answer 4

constant are used to make value same throughout the project

Answer 5

it's mainly use full deceleration of database or configuration of database

Answer 6

in my opinion we use the if we have something and it doesn't change

Answer 7

π es un ejemplo clarísimo