Questionfy free-set-object

content/redirects.yaml

@@ -922,9 +922,6 @@
 - from: /js/s/pad
   to: /js/s/pad-string
   status: 301!
-- from: /js/s/frozen-set
-  to: /js/s/freeze-set-object
-  status: 301!
 - from: /js/s/prefix
   to: /js/s/prefix-css-property
   status: 301!
@@ -2608,3 +2605,9 @@
 - from: /js/s/function-based-array-element-equality
   to: /js/s/all-values-of-array-are-equal
   status: 301!
+- from: /js/s/frozen-set
+  to: /js/s/freeze-set-or-map
+  status: 301!
+- from: /js/s/freeze-set-object
+  to: /js/s/freeze-set-or-map
+  status: 301!

content/snippets/js/s/freeze-set-or-map.md

@@ -0,0 +1,54 @@
+---
+title: Can I freeze a Set or Map in JavaScript?
+shortTitle: Freeze Set or Map
+type: question
+language: javascript
+tags: [array]
+cover: reflection-on-lake
+excerpt: Learn how to create a frozen `Set` or `Map` in JavaScript.
+dateModified: 2024-02-15
+---
+
+Freezing an object is rather simple, using `Object.freeze()`. However, when it comes to freezing a `Set` or `Map`, things get a bit more complicated. The `Set` and `Map` objects have their own methods for adding, deleting and clearing elements, which can be problematic when trying to freeze them.
+
+Luckily, as they're objects after all, you can easily **override these methods** to prevent them from being used.
+
+## Freeze a `Set` object
+
+In order to freeze a `Set` object, you can simply set the `Set.prototype.add()`, `Set.prototype.delete()` and `Set.prototype.clear()` methods to `undefined`. This will effectively prevent them from being used, practically freezing the object. In addition to that, you can use `Object.freeze()` to freeze the `Set` object itself.
+
+```js
+const freezeSet = iterable => {
+  const s = new Set(iterable);
+  s.add = undefined;
+  s.delete = undefined;
+  s.clear = undefined;
+  return Object.freeze(s);
+};
+
+freezeSet([1, 2, 3, 1, 2]);
+/* Set {
+  1, 2, 3,
+  add: undefined, delete: undefined, clear: undefined
+} */
+```
+
+## Freeze a `Map` object
+
+Freezing a `Map` object is very similar to freezing a `Set` object. You can set the `Map.prototype.set()`, `Map.prototype.delete()` and `Map.prototype.clear()` methods to `undefined` and then use `Object.freeze()` to freeze the `Map` object itself.
+
+```js
+const freezeMap = iterable => {
+  const m = new Map(iterable);
+  m.set = undefined;
+  m.delete = undefined;
+  m.clear = undefined;
+  return Object.freeze(m);
+};
+
+freezeMap([['a', 1], ['b', 2]]);
+/* Map {
+  'a' => 1, 'b' => 2,
+  set: undefined, delete: undefined, clear: undefined
+} */
+```