Dictionary in Go

Question

I'm just starting out with Go, and coming from Python I'm trying to find the equivalent of a dict in Python. In Python I would do this:

d = {
    'name': 'Kramer',  # string
    'age': 25          # int
}

I first found the map type, but that only allows for one type of value (it can't handle both ints and strings. Do I really need to create a struct whenever I want to do something like this? Or is there a type I'm missing?

Answer 1

Basically the problem is that it's hard to encounter a requirement to store values of different types in the same map instance in real code.

In your particular case, you should just use a struct type, like this:

type person struct {
  name string
  age  int
}

Initializing them is no harder than maps thanks to so-called "literals":

joe := person{
  name: "Doe, John",
  age:  32,
}

Accessing individual fields is no harder than with a map:

joe["name"] // a map

versus

joe.name // a struct type

---

All in all, please consider reading an introductory book on Go along with your attemps to solve problems with Go, as you inevitably are trying to apply your working knowledge of a dynamically-typed language to a strictly-typed one, so you're basically trying to write Python in Go, and that's counter-productive.

I'd recommend starting with The Go Programming Language.

There are also free books on Go.

Answer 2

That's probably not the best decision, but you can use interface{} to make your map accept any types:

package main

import (
    "fmt"
)

func main() {
    dict := map[interface{}]interface{} {
        1: "hello",
        "hey": 2,
    }
    fmt.Println(dict) // map[1:hello hey:2]
}