Add insertAt

snippets/insertAt.md

@@ -0,0 +1,23 @@
+---
+title: insertAt
+tags: array,intermediate
+---
+
+Mutates the original array to insert the given values at the specified index.
+
+Use `Array.prototype.splice()` with an appropriate index and a delete count of `0`, spreading the given values to be inserted.
+
+```js
+const insertAt = (arr, i, ...v) => {
+  arr.splice(i + 1, 0, ...v);
+  return arr;
+};
+```
+
+```js
+let myArray = [1, 2, 3, 4];
+insertAt(myArray, 2, 5); // myArray = [1, 2, 3, 5, 4]
+
+let otherArray = [2, 10];
+insertAt(otherArray, 0, 4, 6, 8); // otherArray = [2, 4, 6, 8, 10]
+```