Golang使用函数返回两个变量

Question

Assume there is a function that returns two variables.

func num(a,b int) (int,int) {
    return a+b, a-b
}

http://play.golang.org/p/bx05BugelV

And assume I have a function that only takes one int value.

package main

import "fmt"

func main() {
    fmt.Println("Hello, playground")
    _, a := num(1, 2)
    prn(a)

}

func num(a, b int) (int, int) {
    return a + b, a - b
}

func prn(a int) {
    fmt.Println(a)
}

http://play.golang.org/p/VhxF_lbVf4

Is there anyway I can only get the 2nd value (a-b) without having _,a:=num(1,2)?? Something like prn(num(1,2)[1]) <-- this won't work, but I'm wondering if there's a similar way

Thank you

Answer 1

Use a wrapper function. For example,

package main

import "fmt"

func main() {
    _, a := num(1, 2)
    prn(a)
    prn1(num(1, 2))

}

func num(a, b int) (int, int) {
    return a + b, a - b
}

func prn(a int) {
    fmt.Println(a)
}

func prn1(_, b int) {
    prn(b)
}

Output:

-1
-1