Random.Range

Description

Returns a random float within [minInclusive..maxInclusive] (range is inclusive).

If minInclusive is greater than maxInclusive, then the numbers are automatically swapped.

Important: Both the lower and upper bounds are inclusive. Any given float value between them, including both minInclusive and maxInclusive, will appear on average approximately once every ten million random samples.

There is an int overload of this function that operates slightly differently, especially regarding the range maximum. See its docs below.

See Random for details on the algorithm, and for examples of how UnityEngine.Random may be different from other random number generators.

using UnityEngine;

public class ExampleClass : MonoBehaviour
{
    public GameObject prefab;

    // Click the "Instantiate!" button and a new `prefab` will be instantiated
    // somewhere within -10.0 and 10.0 (inclusive) on the x-z plane
    void OnGUI()
    {
        if (GUI.Button(new Rect(10, 10, 100, 50), "Instantiate!"))
        {
            var position = new Vector3(Random.Range(-10.0f, 10.0f), 0, Random.Range(-10.0f, 10.0f));
            Instantiate(prefab, position, Quaternion.identity);
        }
    }
}

Description

Return a random int within [minInclusive..maxExclusive) (Read Only).

The maximum parameter is exclusive, so for example Random.Range(0, 10) returns a value between 0 and 9, each with approximately equal probability.

If minInclusive and maxExclusive are equal, the method returns minInclusive.

If minInclusive is greater than maxExclusive, the input parameters are swapped but retain their inclusivity or exclusivity based on their original positions, which means the method becomes Random.Range(minExclusive, maxInclusive) after swapping.

For example, calling Random.Range(10, 0) is not equivalent to Random.Range(0, 10). Random.Range(10, 0) returns a value between 1 and 10 because 10 becomes an inclusive maximum and 0 becomes an exclusive minimum.

There is a float overload of this function that operates slightly differently, especially regarding the range maximum, refer to its docs above.

Refer to Random for details on the algorithm, and for examples of how UnityEngine.Random may differ from other random number generators.

using UnityEngine;

public class ExampleClass : MonoBehaviour
{
    public GameObject prefab;
    public float zoffset = 10;

    // Click the "Instantiate!" button and a new grid of `prefab` objects will be
    // instantiated with a random number of items in each direction.
    void OnGUI()
    {
        if (GUI.Button(new Rect(10, 10, 100, 50), "Instantiate!"))
        {
            // the grid will always be 1, 2, 3, 4, or 5 prefabs wide
            int xcount = Random.Range(1, 6);
            // the grid will always be 2, 3, or 4 prefabs long
            int ycount = Random.Range(2, 5);

            for (int x = 0; x != xcount; ++x)
            {
                for (int y = 0; y != ycount; ++y)
                {
                    var position = new Vector3(x * 2, zoffset, y * 2);
                    Instantiate(prefab, position, Quaternion.identity);
                }
            }

            zoffset += 2;
        }
    }
}