go / beginner
Snippet
Goroutines: Lightweight Concurrency
Goroutines are lightweight threads managed by the Go runtime, started with the go keyword. They run concurrently (not necessarily parallel) with other code. The main function itself is a goroutine, and the program exits when the main goroutine ends, even if other goroutines are still running. Use time.Sleep or sync.WaitGroup to wait for goroutines to complete. Goroutines are cheap - you can have thousands running simultaneously.
snippet.go
go
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package mainimport ("fmt""time")func greet(name string) {fmt.Printf("Hello, %s!\n", name)}func task(id int) {for i := 1; i <= 3; i++ {fmt.Printf("Task %d: step %d\n", id, i)time.Sleep(100 * time.Millisecond)}}func main() {// Launch goroutine - runs concurrentlygo greet("Alice")go greet("Bob")// Launch multiple concurrent tasksfor i := 1; i <= 3; i++ {go task(i)}// Wait long enough for goroutines to completetime.Sleep(400 * time.Millisecond)fmt.Println("Main function done")}
Breakdown
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go greet("Alice")
Starts a new goroutine - greet runs concurrently with main
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time.Sleep(400 * time.Millisecond)
Main waits long enough for other goroutines to finish
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fmt.Println("Main function done")
May print before all goroutines finish - execution order is not guaranteed