use range in golang code example

Example 1: golang range arrat

for i, num := range nums {
        if num == 3 {
            fmt.Println("index:", i)
        }
    }

Example 2: range in go

kvs := map[string]string{"a": "apple", "b": "banana"}
    for k, v := range kvs {
        fmt.Printf("%s -> %s\n", k, v)
    }