random number

[ankur rathi]

How computer generates random number???

[Chetan Parekh]

They use one or another kind of algorithm. Check API documentation of Random class.

I have not gone thru, but I beleive if you can just open java\util\Random.java file, you will be able to see logic.

[Ulf Dittmer]

Wikipedia: Random Number Generation has a brief introduction, and lots of links for further research. If you're interested in Java code, have a look at the java.util.Random class - its source comes with the JDK and is commented.
[ September 26, 2006: Message edited by: Ulf Dittmer ]

[fred rosenberger]

One could argue that computers do NOT generate random numbers, but PSEUDO random numbers.

there is a defined algorithm for generating the number. If i knew what that algorithm is, and had the proper information, i could tell you exactly what the next numbe would be. therefore, it is not random.

however, most people do not have access to that information, so it works well enough - it simulates a Random Number Generator.

[ankur rathi]

Originally posted by fred rosenberger:
One could argue that computers do NOT generate random numbers, but PSEUDO random numbers.

there is a defined algorithm for generating the number. If i knew what that algorithm is, and had the proper information, i could tell you exactly what the next numbe would be. therefore, it is not random.

however, most people do not have access to that information, so it works well enough - it simulates a Random Number Generator.

We both think more or less same.
Thanks All.

[Stan James]

I saw a neat story about some guys who bought a slot machine identical to those used in several casinos, reverse engineered the random number generator, found it was tied to a clock and they could predict times that would cause a payout. The computer guy got on the phone with a partner in the casino who signaled the player when to pull the lever. Pretty slick.

I keep reading about RNGs that use heat and electronic noise inside the computer instead of algorithms to generate a new number from the one before. I'm sure we'll have quantum RNGs soon enough. Open a box, check the state of the cat for the seed or something like that.