Go中的静态局部变量

Question

Is it possible to define a local variable in Go that can maintain its value from one function call to another? In C, we can do this using the reserved word static.

Example in C:

int func() {
    static int x = 0; 
    x++;
    return x;
}

Answer 1

Use a closure:

Function literals are closures: they may refer to variables defined in a surrounding function. Those variables are then shared between the surrounding function and the function literal, and they survive as long as they are accessible.

It doesn't have to be in global scope, just outside the function definition.

func main() {

    x := 1

    y := func() {
        fmt.Println("x:", x)
        x++
    }

    for i := 0; i < 10; i++ {
        y()
    }
}

(Sample on the Go Playground)