This function generates a random number.
Rnd[(number)]
Returns a value less than 1 but greater than or equal to 0.
The following table shows how the value of number determines the random number that Rnd generates; number is used to seed the random number generator.
If number is |
Rnd generates |
| Less than 0 | The same number every time for each number. |
| Greater than 0 | The next random number in the sequence. |
| Equal to 0 | The most recently generated number. |
| Not supplied | The next random number in the sequence. |
For any specified positive seed, the same number sequence is generated because each successive call to Rnd uses the previously generated number as a seed for the next number in the sequence.
The following code example shows how to produce random integers in a specified range.
Int((upperbound - lowerbound + 1) * Rnd + lowerbound)
In the example, upperbound is the highest number in the range, and lowerbound is the lowest number in the range.
Rnd and Randomize are often used together. When number is negative, Randomize is ignored and a value is returned based solely on number. Seeding Randomize and Rnd with the same values for number produces the same sequence of numbers each time the application runs. To prevent repetition, before calling Rnd use the Randomize statement without an parameter to initialize the random-number generator with a seed based on the system timer.