Questions about Maps

Getting Help
1

For a hands on exercise, I was given the following instructions:

Create a map with a key of TYPE string which is a person’s “last_first” name, and a value of TYPE []string which stores their favorite things. Store three records in your map. Print out all of the values, along with their index position in the slice.
bond_james, Shaken, not stirred, Martinis, Women
moneypenny_miss, James Bond, Literature, Computer Science
no_dr, Being evil, Ice cream, Sunsets

This is what I came up with:
https://play.golang.org/p/wk3fziQomX5

What did I do wrong?

2

After listening to the teacher’s video, I got
https://play.golang.org/p/nkz9O0Q6Lg7

So I think I’m good. I just need to study this a little more.

1 Like
3

It looks good so far. You just need to add the part that prints the indices and values of the slices.

4

You just need to add the part that prints the indices and values of the slice

What’s wrong here: https://play.golang.org/p/bfCtHrqFZMx

5

The missing dot (.) between fmt and Println.

Reading error messages might help to solve those problems.

2 Likes
6

I have trouble understanding some error messages, but others I am learning to figure out. I don’t know what that particular error message means: unexpected Println at end of statement

7

This is maybe what you want to do. https://play.golang.org/p/UopgdBH15pJ
The map value is a []string. So you need to either create a list in place or create it as a separate variable and then assign it.

8

Use backticks for multiline strings. Also use untyped composite literal instead, which is shorter (see https://github.com/golang/go/issues/12854)
https://play.golang.org/p/9sgbLZaZjsl

9

That works :slight_smile:

10

Thanks :slight_smile:

This part I don’t understand:
var x []string = {“a”, “b”, “c”}
var m map[string]int = {“a”: 1}

type T struct {
V int
}
var s []*T = {{0}, {1}, {2}}

a := {1, 2, 3} // error: left-hand-type has no type specified

11

Also this:
Go already allows the elision of the type of a composite literal under certain circumstances. This proposal extends that permission to all occasions when the literal type can be derived.

12

The type cannot be derived in case of a := {1, 2, 3}, since it can possibly be int/uint of some length. I guess this is why it’s not allowed to omit type in slice literal.

13

This is cool!

14

Use backticks for multiline strings. Also use untyped composite literal instead, which is shorter

This is interesting. And I now understand it better than when I read it the first time, although I still need work

15

This is hard for me to understand; maybe because I’ve had 0 exercise today. I’ll come back to this later.

16

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