CODEWITHSUNDEEP
actionscript-3flashint
Mark Fox
Mark Fox

Reputation: 8924

In AS3 what will getTimer() return when the value is larger than the maximum int

Per Adobe getTimer() is:

Used to compute relative time. For a Flash runtime processing ActionScript 3.0, this method returns the number of milliseconds that have elapsed since the Flash runtime virtual machine for ActionScript 3.0 (AVM2) started.

Since getTimer returns a int which:

The int class lets you work with the data type representing a 32-bit signed integer. The range of values represented by the int class is -2,147,483,648 (-2^31) to 2,147,483,647 (2^31-1)

What will getTimer() return after the 2,147,483,647 millisecond? That would roughly be 24.85 straight days of running I think. Not a usual situation but for digital signage and kiosk context that is entirely feasible.

Should getTimer() be avoided in these situations? Would a Date.UTC() object be safer since it returns a Number type?

Upvotes: 4

Views: 2176

Answers (1)

Josh
Josh

Reputation: 8159

My guess is it will loop back on itself, just as int will.

var nt:int = int.MAX_VALUE + 10; //outputs -2147483639
var nt2:int = int.MIN_VALUE + 9; //outputs -2147483639

As you can see, MAX + 10 is the same as MIN + 9 (have to account for the min value itself, obviously). So when you hit that 24 day mark, it will possibly look like -24 days and start going back up.

There is also a chance that the function itself doesn't return the actual time, but something along these lines:

return timer % int.MAX_VALUE;

That will reset the time each time it hits the MAX_VALUE to 0, using simple modulus. I honestly would not be surprised if this is what they do (since you don't want a negative runtime, obviously)

Upvotes: 1

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