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VB.NET Language in a Nutshell, Second Edition by Steven Roman PhD, Paul Lomax, Ron Petrusha

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Name

Rnd Function

Class

Microsoft.VisualBasic.VBMath

Syntax

Rnd[(number)]
number (optional; Single)

Any valid numeric expression that serves as a seed value

Return Value

A Single data type random number

Description

Returns a random number

Rules at a Glance

  • The behavior of the Rnd function is determined by number, as described in the following table:

Number

Rnd generates

< 0

The same number each time, using seed as the seed number

> 0

The next random number in the current sequence

0

The most recently generated number

Not supplied

The next random number in the current sequence

  • The Rnd function always returns a value between and 1.

  • If number is not supplied, the Rnd function will use the last number generated as the seed for the next generated number. This means that given an initial seed (seed), the same sequence will be generated if number is not supplied on subsequent calls.

Example

The following example uses the Randomize procedure along with the Rnd function to fill 100 cells of an Excel worksheet with random numbers. It requires that a reference to the Microsoft Excel Object Library be added to the project. It also leaves the instance of Excel running once the code has finished execution.

 Public Sub GenerateRandomNumbers( ) Dim oApp As New Excel.Application( ) Dim objSheet As Excel.Worksheet Dim intRow, intCol As Integer oApp.Visible = True objSheet = oApp.Workbooks.Add.Worksheets(1) Randomize( ) ' Set the color of the input text to blue objSheet.Cells.Font.ColorIndex = 5 ...

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