Rename js snippets

snippets/js/s/function-based-array-intersection.md

@@ -0,0 +1,25 @@
+---
+title: Array intersection based on function
+type: snippet
+language: javascript
+tags: [array]
+cover: digital-nomad-2
+dateModified: 2020-10-20T23:02:01+03:00
+---
+
+Returns the elements that exist in both arrays, using a provided comparator function.
+
+- Use `Array.prototype.filter()` and `Array.prototype.findIndex()` in combination with the provided comparator to determine intersecting values.
+
+```js
+const intersectionWith = (a, b, comp) =>
+  a.filter(x => b.findIndex(y => comp(x, y)) !== -1);
+```
+
+```js
+intersectionWith(
+  [1, 1.2, 1.5, 3, 0],
+  [1.9, 3, 0, 3.9],
+  (a, b) => Math.round(a) === Math.round(b)
+); // [1.5, 3, 0]
+```