Prepare repository for merge

javascript/snippets/super-set.md

@@ -0,0 +1,24 @@
+---
+title: Superset of iterable
+type: snippet
+tags: [array]
+cover: waves-from-above-2
+dateModified: 2020-10-22T20:24:30+03:00
+---
+
+Checks if the first iterable is a superset of the second one, excluding duplicate values.
+
+- Use the `Set` constructor to create a new `Set` object from each iterable.
+- Use `Array.prototype.every()` and `Set.prototype.has()` to check that each value in the second iterable is contained in the first one.
+
+```js
+const superSet = (a, b) => {
+  const sA = new Set(a), sB = new Set(b);
+  return [...sB].every(v => sA.has(v));
+};
+```
+
+```js
+superSet(new Set([1, 2, 3, 4]), new Set([1, 2])); // true
+superSet(new Set([1, 2, 3, 4]), new Set([1, 5])); // false
+```