4 led's parallel resistor advice?

[amz-fx]

They buy many thousand LEDs and sort them for forward voltage.

I don't think they sort. I bought a cheap flashlight with 3 white LEDs and it had three AAA batteries connected to the LEDs which were in parallel. No dropping resistor. As the battery voltage dropped, one LED would begin to dim, then another. All 3 would stay lit but eventually one carried the majority of the load.

Why spend the time/money sorting when you can make it work without?    Also, save a fraction of a penny on the resistor(s).

I switched the LEDs in the flashlight for ultraviolet versions to use as an inspection tool. Added dropping resistors too.

@GGBB: There is nothing technical about it, just the way some datasheets are written. The 3v is a typical operating parameter and not a spec for the forward voltage.

regards, Jack