golang channel 怎么判断是否读取完成？求老司机指点！

Question

r:=make(chanint)forn:=0;n

Answer 1

import"sync"
funcmain(){
rNum:=100000
r:=make(chanint,rNum)
varwgsync.WaitGroup
forn:=0;nwg.Add(1)
gofunc(xint,rchanint){
deferwg.Done()
ifx%3==0&&x%23==0{
r<-x
}
}(n,r)
}
wg.Wait()
close(r)
fori:=ranger{
println(i)
}
}
                            

Answer 2

packagemain
import(
"sync"
)
funcmain(){
wait:=sync.WaitGroup{}
r:=make(chanint)
forn:=0;n<100000;n++{
wait.Add(1)
gofunc(xint,rchanint){
deferwait.Done()
ifx%3==0&&x%23==0{
r<-x
}
}(n,r)
}
gofunc(){
wait.Wait()
close(r)
}()
fori:=ranger{
println(i)
}
}