Functions

(S) first-class functions

Both languages treat functions as first-class citizens. Both allow functions to be passed as arguments, to be a returned value, to be nested, and have closures.

Function nesting in Javascript can be done both with named and anonymous functions, while in Go this can only be done with anonymous functions.

(D) Multiple returns

Go functions can return multiple values

Go

func hello() (string, string) {
    return "hello", "world"
}

func main() {
    a, b := hello()
    fmt.Println(a, b)
}

Javascript cannot, however by using destructuring assignment syntax, we can get a similar behavior

JS

function hello() {
  return ["hello", "world"];
}

var [a, b] = hello();
console.log(a,b);

(S) IIFE

JS

(function () {
  console.log('hello');
}());

Go

func main() {
    func() {
        fmt.Println("Hello")
    }()
}

(S) Closures

Both languages have closures. Both require caution when creating closures inside loops. Here are examples in both languages that demonstrate a similar technique to bypass the closure/loop trap:

JS (with bug)

var i = 0;
for (;  i < 10 ; i++) {
  setTimeout((function() {console.log(i);}),0);
}

JS (solved) (note that using for(let i=0; … instead of var is a more practical solution)

var i = 0;
for (;  i < 10 ; i++) {
  (function (i) {
    setTimeout((function() {console.log(i);}),0);
  }(i));
}

Go (with bug)

var wg sync.WaitGroup
wg.Add(10)
for i := 0; i < 10; i++ {
    go func() {
        defer wg.Done()
        fmt.Println(i)
    }()
}
wg.Wait()

Go (solved)

var wg sync.WaitGroup
wg.Add(10)
for i := 0; i < 10; i++ {
    go func(i int) {
        defer wg.Done()
        fmt.Println(i)
    }(i)
}
wg.Wait()