Java Generate Random Number Between Two Given Values [duplicate]

I would like to know how to generate a random number between two given values.

I am able to generate a random number with the following:

Random r = new Random();

for(int i = 0; i < a.length; i++){
    for(int j = 0; j < a[i].length; j++){
        a[i][j] = r.nextInt();
    }

}

However, how can I generate a random number between 0 and 100 (inclusive)?


Solution 1:

You could use e.g. r.nextInt(101)

For a more generic "in between two numbers" use:

Random r = new Random();
int low = 10;
int high = 100;
int result = r.nextInt(high-low) + low;

This gives you a random number in between 10 (inclusive) and 100 (exclusive)

Solution 2:

Assuming the upper is the upper bound and lower is the lower bound, then you can make a random number, r, between the two bounds with:

int r = (int) (Math.random() * (upper - lower)) + lower;

Solution 3:

int Random = (int)(Math.random()*100);

if You need to generate more than one value, then just use for loop for that

 for (int i = 1; i <= 10 ; i++)
       {
        int Random = (int)(Math.random()*100);
        System.out.println(Random);
       }

If You want to specify a more decent range, like from 10 to 100 ( both are in the range )

so the code would be :

   int Random =10 +  (int)(Math.random()*(91));
   /* int Random = (min.value ) + (int)(Math.random()* ( Max - Min + 1));
  *Where min is the smallest value You want to be the smallest number possible to       
  generate and Max is the biggest possible number to generate*/

Solution 4:

Like this,

Random random = new Random();
int randomNumber = random.nextInt(upperBound - lowerBound) + lowerBound;

Solution 5:

Use Random.nextInt(int).

In your case it would look something like this:

a[i][j] = r.nextInt(101);