package go_koans func aboutMaps() { ages := map[string]int{ "bob": 10, "joe": 20, "dan": 30, } age := ages["bob"] assert(age == __int__) // map syntax is warmly familiar age, ok := ages["bob"] assert(ok == __bool__) // with a handy multiple-assignment variation age, ok = ages["steven"] assert(age == __int__) // the zero value is used when absent assert(ok == __boolean__) // though there are better ways to check for presence assert(len(ages) == __int__) // length is based on keys ages["bob"] = 99 assert(ages["bob"] == __int__) // values can be changed for keys ages["steven"] = 77 assert(ages[__string__] == 77) // new ones can be added delete(ages, "steven") age, ok = ages["steven"] assert(ok == __boolean__) // key/value pairs can be removed }