Go中是否有与此JS表达式等效的代码？

Let's say we have 2 strings, str1 and str2. I want a new variable str3 to equal str1, or if str1 is empty then equal str2.

In JS I would write:

var str3 = str1 || str2

While in Go I have to do it like:

str3 := str1
if str1 == "" {
    str3 = str2
}

which is a little bit too verbose imo. Is there an equivalent expression as the one in JS?

Is there an equivalent expression as the one in JS?

No, but if you find yourself doing this often, you could write a function that does what you're trying to accomplish:

func strs(s ...string) string {
    if len(s) == 0 {
        return ""
    }
    for _, str := range s[:len(s)-1] {
        if str != "" {
            return str
        }
    }
    return s[len(s)-1]
}

Usage:

str3 := strs(str1, str2)

https://play.golang.org/p/Gl_06XDjW4

There is no equivalent operation in Go. You have to do it with an if (or a switch, but that's even more verbose). I would write it like this:

var str3 string
if str1 != "" {
    str3 = str1
} else {
    str3 = str2
}