Interface Map<K, V>

The Map object holds key-value pairs but doesn't remember the original insertion order of the keys (like JS would). Any value (both objects and primitive values) may be used as either a key or a value. Maps are the best choice for dynamic indexing/newindexing, whereas Objects are better for explicit indexing.

Example

const playerData = new Map<Player, PlayerData>();

function f(plr: Player) {
    const data = playerData.get(plr); // `data` could be undefined
    if (data) { // check to make sure `data` is defined
        print(`${plr.Name} has ${data.NumItems} item${data.NumItems === 1 ? "" : "s"}`);
    }
}
// Do not use Maps when you can easily explicitly index from an object:

// TS doesn't assume "x" | "y" are the only possible fields.
// You could manually type this as Map<"x" | "y", number>
const point = new Map([["x", 5], ["y", 10]]);
// this is typed as possibly undefined, because "x" can be deleted
print(point.get("x"));

// Instead use an object
const point = { x: 5, y: 10 };
print(point.y++);
point.z = 15 // error!
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