`go fn()` spawns a goroutine. To wait for several to finish, use `sync.WaitGroup` — call `Add` before spawning, `Done` (deferred) inside, `Wait` to block until all are done.
Go
package main
import (
"fmt"
"sync"
"time"
)
func main() {
var wg sync.WaitGroup
urls := []string{"a", "b", "c", "d"}
for _, u := range urls {
wg.Add(1) // increment BEFORE go
go func(url string) {
defer wg.Done() // decrement when goroutine exits
time.Sleep(100 * time.Millisecond)
fmt.Println("fetched", url)
}(u) // pass `u` as arg — avoid closure capture bug
}
wg.Wait() // blocks until all Done() called
fmt.Println("all done")
}Save your own code snippets
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