Rename js snippets

snippets/js/s/array-is-contained-in.md

@@ -0,0 +1,33 @@
+---
+title: Array is contained in other array
+type: snippet
+language: javascript
+tags: [array]
+author: chalarangelo
+cover: island-corridor
+dateModified: 2020-10-22T20:23:47+03:00
+---
+
+Checks if the elements of the first array are contained in the second one regardless of order.
+
+- Use a `for...of` loop over a `Set` created from the first array.
+- Use `Array.prototype.some()` to check if all distinct values are contained in the second array.
+- Use `Array.prototype.filter()` to compare the number of occurrences of each distinct value in both arrays.
+- Return `false` if the count of any element is greater in the first array than the second one, `true` otherwise.
+
+```js
+const isContainedIn = (a, b) => {
+  for (const v of new Set(a)) {
+    if (
+      !b.some(e => e === v) ||
+      a.filter(e => e === v).length > b.filter(e => e === v).length
+    )
+      return false;
+  }
+  return true;
+};
+```
+
+```js
+isContainedIn([1, 4], [2, 4, 1]); // true
+```