[go-nuts] differences between pointer and value slice in for-range loop

[Fei Ding]

Hi:

Please check this code snippet:

package main

import (  
    "fmt"
    "time"
)

type field struct {  
    name string
}

func (p *field) print() {  
    fmt.Println(p.name)
}

func main() {
    fmt.Println("use values:")

    // use values in range loop and go rountines
    values := []field{{"one"},{"two"},{"three"}}
    for _, v := range values {
        go v.print()
    }

    time.Sleep(time.Second)

    fmt.Println()
    fmt.Println("use pointers:")

    // use pointers in range loop and go rountines
    poniters := []*field{{"one"},{"two"},{"three"}}
    for _, v := range poniters {
        go v.print()
    }

    time.Sleep(time.Second)
}

Link here: https://play.golang.org/p/cdryPmyWt5

The code above is going to check the differences between pointers and 
values in a for loop, while go statement is also used at the same time. For 
code:

    values := []field{{"one"},{"two"},{"three"}}
    for _, v := range values {
        go v.print()
    }

we know that the console will print *three three three* as result, because 
for loop runs into its end before go routines start executing, which write 
*v* as the last element of the slice. But what about pointers? 

    poniters := []*field{{"one"},{"two"},{"three"}}
    for _, v := range poniters {
        go v.print()
    }

It seems to print* one two three*, why?

Thanks.







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