package main


func a () (int, int) {
	return 6,7
}

func b() int {
	return 8
}

func commaOk() {
   
   var i interface{} = "hello"


   s, ok := i.(string)
   assert(ok)
   assert(s == "hello")
   
   s1 := i.(string)
   assert(s1 == "hello")


	
   	m := map[int]int{1:10, 2:20}
   	int1, ok := m[1]
	assert(int1 == 10)
	assert(ok)
	int2 := m[2]
	assert(int2 == 20)

	t1, t2 := a()
	assert(t1 == 6)
	assert(t2 == 7)
	t3 := b()
	assert(t3 == 8)

    t01, t02 := 33, m[2]
    assert(t01 == 33)
	assert(t02 == 20)
}

func main() {
    var s1 = map[int]int{1:2, 3: 888}
    var v = s1[1]
    var v2 = s1[100]
    s1[0], v, v2 = 8, s1[100], s1[1]
    var v3 = s1[0]
    s1[2] = 3
    assert(v == 0)
    assert(v2 == 2)
    assert(v3 == 8)
    assert(s1[2] == 3)
    assert(s1[3] == 888)

    commaOk()
}