golangRun multiple goroutines and wait for them to finish

package main

import "fmt"
import "sync"

func hi(idx int) {
  fmt.Println(idx)
}

func main() {
  var wg sync.WaitGroup
  
  for i := 1; i <= 3; i++ {
    i := i
    wg.Add(1)
    go func() {
      defer wg.Done()
      hi(i)
    }()
  }
  
  wg.Wait()
}ctrl + cgithub

`func main() {` declare `main` function that will be launched automatically	`func hi` function that we will call in parallel
`wg sync.WaitGroup` declare new wait group	`i := i` used not to mix `i` values in closure
`wg.Add(1)` increase waiting counter on each iteration by `1`	`defer wg.Done()` call `hi()` function in closure
`wg.Wait()` will wait for all goroutines to finish

Usage example

package main

import "fmt"
import "sync"

func hi(idx int) {
  fmt.Println(idx)
}

func main() {
  var wg sync.WaitGroup

  for i := 1; i <= 3; i++ {
    i := i
    wg.Add(1)
    go func() {
      defer wg.Done()
      hi(i)
    }()
  }

  wg.Wait()
}

output

3
1
2

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golangRun multiple goroutines and wait for them to finish

Usage example

output

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