Are there constants in JavaScript?

Question

Is there a way to use constants in JavaScript?

If not, what\'s the common practice for specifying variables that are used as constants?

Answer 1

Introducing constants into JavaScript is at best a hack.

A nice way of making persistent and globally accessible values in JavaScript would be declaring an object literal with some "read-only" properties like this:

            my={get constant1(){return "constant 1"},
                get constant2(){return "constant 2"},
                get constant3(){return "constant 3"},
                get constantN(){return "constant N"}
                }

you'll have all your constants grouped in one single "my" accessory object where you can look for your stored values or anything else you may have decided to put there for that matter. Now let's test if it works:

           my.constant1; >> "constant 1" 
           my.constant1 = "new constant 1";
           my.constant1; >> "constant 1" 

As we can see, the "my.constant1" property has preserved its original value. You've made yourself some nice 'green' temporary constants...

But of course this will only guard you from accidentally modifying, altering, nullifying, or emptying your property constant value with a direct access as in the given example.

Otherwise I still think that constants are for dummies. And I still think that exchanging your great freedom for a small corner of deceptive security is the worst trade possible.