From b8b56d24f266f2a7c5af5105bc8b82200e6bf1e7 Mon Sep 17 00:00:00 2001
From: Rohit Tanwar <31792358+kriadmin@users.noreply.github.com>
Date: Sat, 20 Jan 2018 20:51:34 +0530
Subject: [PATCH 1/3] zipWith

---
 snippets/zipWith.md | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 snippets/zipWith.md

diff --git a/snippets/zipWith.md b/snippets/zipWith.md
new file mode 100644
index 000000000..024dca82f
--- /dev/null
+++ b/snippets/zipWith.md
@@ -0,0 +1,22 @@
+### zipWith
+
+This method is like [zip](https://30secondsofcode.org/#zip) except that it accepts a function (`fn`) as the last value to specify how grouped values should be combined. 
+
+The function is invoked with the elements of each group: `(...group)`.
+
+``` js
+const zipWith = (...arrays) => {
+  const length = arrays.length;
+  let fn = length > 1 ? arrays[length - 1] : undefined;
+  fn = typeof fn == 'function' ? (arrays.pop(), fn) : undefined;
+  const maxLength = Math.max(...arrays.map(x => x.length));
+  const result =  Array.from({ length: maxLength }).map((_, i) => {
+    return Array.from({ length: arrays.length }, (_, k) => arrays[k][i]);
+  })
+  return fn ? result.map(arr => fn(...arr)) : result;
+}
+```
+
+``` js
+zipWith([1, 2], [10, 20], [100, 200], (a,b,c) => a + b + c); // [111,222]
+```

From c98c5a5bcc8a28bdc7c1c8854821ad3edf96e03d Mon Sep 17 00:00:00 2001
From: Rohit Tanwar <31792358+kriadmin@users.noreply.github.com>
Date: Sun, 21 Jan 2018 12:21:22 +0530
Subject: [PATCH 2/3] Update zipWith.md

---
 snippets/zipWith.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/snippets/zipWith.md b/snippets/zipWith.md
index 024dca82f..b9dc53acc 100644
--- a/snippets/zipWith.md
+++ b/snippets/zipWith.md
@@ -19,4 +19,5 @@ const zipWith = (...arrays) => {
 
 ``` js
 zipWith([1, 2], [10, 20], [100, 200], (a,b,c) => a + b + c); // [111,222]
+zipWith([1, 2, 3], [10, 20], [100, 200], (a,b,c) => (a != null ? a : 'a') + (b != null ? b:'b') + (c != null ? c : 'c')); // [111, 222, '3bc]
 ```

From 5323cc7cad825734ab8b0ca3806c0f698f5709f4 Mon Sep 17 00:00:00 2001
From: Angelos Chalaris <chalarangelo@gmail.com>
Date: Tue, 23 Jan 2018 15:59:43 +0200
Subject: [PATCH 3/3] Updated description, tags

---
 snippets/zipWith.md | 10 +++++++---
 tag_database        |  1 +
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/snippets/zipWith.md b/snippets/zipWith.md
index b9dc53acc..e50b9a928 100644
--- a/snippets/zipWith.md
+++ b/snippets/zipWith.md
@@ -1,8 +1,12 @@
 ### zipWith
 
-This method is like [zip](https://30secondsofcode.org/#zip) except that it accepts a function (`fn`) as the last value to specify how grouped values should be combined. 
+Creates an array of elements, grouped based on the position in the original arrays and using function as the last value to specify how grouped values should be combined.
 
-The function is invoked with the elements of each group: `(...group)`.
+Check if the last argument provided in a function.
+Use `Math.max()` to get the longest array in the arguments.
+Creates an array with that length as return value and use `Array.from()` with a map-function to create an array of grouped elements.
+If lengths of the argument-arrays vary, `undefined` is used where no value could be found.
+The function is invoked with the elements of each group `(...group)`.
 
 ``` js
 const zipWith = (...arrays) => {
@@ -19,5 +23,5 @@ const zipWith = (...arrays) => {
 
 ``` js
 zipWith([1, 2], [10, 20], [100, 200], (a,b,c) => a + b + c); // [111,222]
-zipWith([1, 2, 3], [10, 20], [100, 200], (a,b,c) => (a != null ? a : 'a') + (b != null ? b:'b') + (c != null ? c : 'c')); // [111, 222, '3bc]
+zipWith([1, 2, 3], [10, 20], [100, 200], (a,b,c) => (a != null ? a : 'a') + (b != null ? b:'b') + (c != null ? c : 'c')); // [111, 222, '3bc']
 ```
diff --git a/tag_database b/tag_database
index d1cd81502..6b69c3f7d 100644
--- a/tag_database
+++ b/tag_database
@@ -216,3 +216,4 @@ words:string,regexp
 yesNo:utility,regexp
 zip:array
 zipObject:array,object
+zipWith:array,advanced