自成一体的围棋与 c 的三元运算符等价吗？

Question

In C/C++ (and many languages of that family), a common idiom to declare and initialize a variable depending on a condition uses the ternary conditional operator :

int index = val > 0 ? val : -val

Go doesn't have the conditional operator. What is the most idiomatic way to implement the same piece of code as above ? I came to the following solution, but it seems quite verbose

var index int

if val > 0 {
    index = val
} else {
    index = -val
}

Is there something better ?

转载于:https://stackoverflow.com/questions/19979178/what-is-the-idiomatic-go-equivalent-of-cs-ternary-operator

Answer 1

As pointed out (and hopefully unsurprisingly), using if+else is indeed the idiomatic way to do conditionals in Go.

In addition to the full blown var+if+else block of code, though, this spelling is also used often:

index := val
if val <= 0 {
    index = -val
}

and if you have a block of code that is repetitive enough, such as the equivalent of int value = a <= b ? a : b, you can create a function to hold it:

func min(a, b int) int {
    if a <= b {
        return a
    }
    return b
}

...

value := min(a, b)

The compiler will inline such simple functions, so it's fast, more clear, and shorter.