Maps in Odin

A harbor registry in a map: make, index, the ok idiom, and iteration.

package main

import "core:fmt"

main :: proc() {
    // make allocates from the context allocator; delete cleans up.
    berths := make(map[string]int)
    defer delete(berths)
    berths["Persephone"] = 9
    berths["Skua"] = 4

    // Indexing a missing key yields the zero value; the ok form tells.
    spot, ok := berths["Dreadnought"]
    fmt.println("unknown ship:", spot, ok)

    for ship, berth in berths {
        fmt.printfln("%s moors at %d", ship, berth)
    }
}

How it works

1. make(map[string]int) allocates from the context allocator; delete cleans up.
2. A missing key yields the zero value; spot, ok := tells you it was missing.
3. for ship, berth in berths walks key and value together.

Keywords and builtins used here

• defer
• delete
• for
• import
• in
• int
• make
• map
• package
• proc
• string

The run, in numbers

Lines

19

Characters to type

428

Tokens

90

Three-star pace

70 tpm

At the three-star pace of 70 tokens a minute, this run takes about 77 seconds.

Type this snippet

Step 3 of 3 in Collections, step 12 of 27 in Language basics.

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Maps in other languages

• Elixir
• Erlang
• Go
• Java
• Scala