Why Does Go's `rand.Intn` Sometimes Generate the Same Value?

Troubleshooting rand.Intn Generating Same Value

The Go example provided in the link indeed returns the same value for rand.Intn(10) unless modified to initialize the random number generator. Here's an explanation:

1. Uninitialized Random Number Source:

   • rand.Intn and other functions in the rand package use the global Source to generate random numbers.
   • By default, this Source is not initialized, leading to a deterministic sequence.
   • To initialize the Source, use rand.Seed(time.Now().UnixNano()).

2. Go Playground Caching:

   • The Go Playground, where the example is run, often caches results to improve performance.
   • This caching can affect the output of random number generation, making it appear deterministic.

To resolve these issues and obtain random numbers consistently, consider the following steps:

1. Initialize the random number generator using rand.Seed(time.Now().UnixNano()).
2. If running the example on the Go Playground, clear the output before running to avoid caching.

By following these steps, you can generate random numbers using rand.Intn effectively and avoid receiving the same value repeatedly.

The above is the detailed content of Why Does Go's `rand.Intn` Sometimes Generate the Same Value?. For more information, please follow other related articles on the PHP Chinese website!