如何在golang中仅显示多值结果的一个输出

Question

Recently, I studied that Golang can return multiple result for a function. So I write a function:

func store(x, y int) (int, int) {
    return x + y, x - y
}

After this I write the following code:

func main() {
    a, b := store(6, 4)
    fmt.Println(a, b)
} 

And, the result is:

10 2

This is working fine.

But if I want to print only a, then how can I do this?

func main() {
    a, b := store(6, 4)
    fmt.Println(a)
}

Result:

tmp/sandbox683412938/main.go:12:19: b declared and not used

Also, why I can't write:

func main() {
    a := store(6, 4) // ???
    fmt.Println(a)
}

Please, guide me.

Answer 1

You can use underscore placeholder (blank identifier) like this:

a, _ := store(6, 4)
fmt.Println(a)

Output:

10

Here's the complete example:

package main

import (
    "fmt"
)

func store(x, y int) (int, int) {
    return x + y, x - y
}

func main() {
    a, _ := store(6, 4)
    fmt.Println(a)
}

Live example: https://play.golang.org/p/Z366BhtRA0