Is this a valid way to assign a random number to a variable?

Question

I have seen a lot of different ways to generate random numbers in between a certain range. Just today I came across the following piece of code. but upon doing research, I did not see anybody describe it this way.

Random ran = new Random();
int j = ran.nextInt(5+10);

My question is, does the code above assign a random integer to j between the numbers of 5 and 10? If so, what if you wrote the second line of code like this int j = rgen.nextInt(10+5);

What kind of question is that @Daniel? Of course it's a serious question. — Omar N, Nov 21 '15 at 18:15
I agree it's a bit naive... but I'm no sure it deserves a downvote. — Dima Maligin, Nov 21 '15 at 18:16
I wonder why people keep saying this is not a worthy question. I am a beginner and trying to learn the different methods of assigning a random int to a variable. — Omar N, Nov 21 '15 at 18:19
What happened when you ran your code a few times? What does the javadoc of `Random` say it does? — Sotirios Delimanolis, Nov 21 '15 at 18:22
What do you think `5+10` does? Do you think it's different from `10+5`? Why do you think so? What do you think method arguments are? — Sotirios Delimanolis, Nov 21 '15 at 18:23
I think it sets a range between max and min, but I did not see this way of doing it in my research. Just wanted clarification on it. — Omar N, Nov 21 '15 at 18:26

score 3 · Accepted Answer · answered Nov 21 '15 at 18:13

3

To generate a random int within [min, max[:

Random r = new Random();
int number = r.nextInt(max - min) + min;

So in your case:

int j = r.nextInt(10 - 5) + 5;

answered Nov 21 '15 at 18:13

Jean Logeart

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Thank you for the help! This helps clarify it. Last question, why do you add the min value outside the bracket? – Omar N Nov 21 '15 at 18:21

Is this a valid way to assign a random number to a variable?

1 Answers1