Golang if Else switch

Package Mainimport ("FMT" "Runtime" "StrConv") func main () {num: = if runtime. GOOS = = "Windows" {FMT. Println ("----------Windows--------")} else {fmt. PRINTLN ("------not----Windows--------")} if num > {fmt. Println ("-------Greater than")} else if num = = {FMT. Println ("-------equals")} else {fmt. Println ("-------not much more than")} orig: = "abc" val, Error: = StrConv. Atoi (orig) fmt. Println ("-------an--------", val) if error! = Nil {fmt. Println ("-------An is not a digital--------")//return//os. Exit (1)//terminates the operation of the program at the same time as the error occurred} val = val + 5 fmt. Println ("----------Val", val) switch num {case 100:fmt. Println ("-------") case 200:fmt. Println ("-------") default:fmt. Println ("-------")} switch {case num = = 100:fmt.    Println ("--1-----"); Fallthrough; Case num > 200:fmt.    PRINTLN ("---2----"); Fallthrough;      Default  Fmt. Println ("--3-----10")}}