What is a WaitGroup in Go?

Can you explain what a WaitGroup is in Go?

A WaitGroup in Go is a synchronization primitive that helps wait for a collection of goroutines to finish executing.

How do I use a WaitGroup in my Go program?

You can use a WaitGroup by creating an instance, calling Add() to set the number of goroutines to wait for, and then calling Done() when each goroutine finishes.

Can you show me a code example?

Sure! Here's a simple example:

var wg sync.WaitGroup

for i := 0; i < 5; i++ {
    wg.Add(1)
    go func(i int) {
        defer wg.Done()
        fmt.Println("Goroutine", i)
    }(i)
}

wg.Wait()

What happens if I forget to call Done()?

If you forget to call Done(), the WaitGroup will wait indefinitely, causing your program to hang.