简单并发[重复]
问题描述：
This question already has an answer here:
- No output from goroutine in Go 3 answers
Can someone explain how this works:
package main
import (
"fmt"
"time"
)
func say(s string) {
for i := 0; i < 5; i++ {
time.Sleep(100 * time.Millisecond)
fmt.Println(s)
}
}
func main() {
say("world")
}
But this doesnt work once i add the word go to the routine in main
package main
import (
"fmt"
"time"
)
func say(s string) {
for i := 0; i < 5; i++ {
time.Sleep(100 * time.Millisecond)
fmt.Println(s)
}
}
func main() {
go say("world")
}
I think its because its finishing before executing the goroutine.
</div>
答
The "world" goroutine does not run or complete because main returns and the program exits.
When that function invocation returns, the program exits. It does not wait for other (non-main) goroutines to complete. https://golang.org/ref/spec#Program_execution