From 7d50f43c13131e2942002b55e9c016357b1a94bf Mon Sep 17 00:00:00 2001
From: Rohit Tanwar <31792358+kriadmin@users.noreply.github.com>
Date: Wed, 3 Jan 2018 14:32:35 +0530
Subject: [PATCH 1/5] Create luhnCheck.md

---
 snippets/luhnCheck.md | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 snippets/luhnCheck.md

diff --git a/snippets/luhnCheck.md b/snippets/luhnCheck.md
new file mode 100644
index 000000000..a6f2cbfd1
--- /dev/null
+++ b/snippets/luhnCheck.md
@@ -0,0 +1,25 @@
+### luhnCheck
+
+Implementation of the [Luhn Algorithm](https://en.wikipedia.org/wiki/Luhn_algorithm) used to validate a variety of identification numbers, such as credit card numbers, IMEI numbers, National Provider Identifier numbers etc.
+Works with numbers and strings alike
+``` js 
+const luhnCheck = num => { 
+    let arr = (num+'').split('').reverse()
+    let lastDigit = arr.splice(0,1)
+    let sum = arr.reduce((acc,val,i) => {
+	    val = parseInt(val)
+    	if(i%2!==0) return acc + val
+    	else{
+		    val = (val * 2)%9 || 9
+		    return acc+ val }
+        },0)
+     sum += parseInt(lastDigit)
+     return sum%10 === 0
+ }
+```
+```js
+ luhnCheck("4485275742308327"); //true
+ luhnCheck(4485275742308327); //true
+ luhnCheck(6011329933655299); // true
+ luhnCheck(123456789); //false
+```

From 10652a52f397fbef60494e87973d5b74ad814a92 Mon Sep 17 00:00:00 2001
From: Rohit Tanwar <31792358+kriadmin@users.noreply.github.com>
Date: Wed, 3 Jan 2018 17:44:36 +0530
Subject: [PATCH 2/5] Update luhnCheck.md

---
 snippets/luhnCheck.md | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/snippets/luhnCheck.md b/snippets/luhnCheck.md
index a6f2cbfd1..4ab440d43 100644
--- a/snippets/luhnCheck.md
+++ b/snippets/luhnCheck.md
@@ -6,13 +6,7 @@ Works with numbers and strings alike
 const luhnCheck = num => { 
     let arr = (num+'').split('').reverse()
     let lastDigit = arr.splice(0,1)
-    let sum = arr.reduce((acc,val,i) => {
-	    val = parseInt(val)
-    	if(i%2!==0) return acc + val
-    	else{
-		    val = (val * 2)%9 || 9
-		    return acc+ val }
-        },0)
+    let sum = arr.reduce((acc,val,i) =>  (acc,val,i) => i%2!==0 ? acc + parseInt(val) : acc + (parseInt(val) * 2)%9 || 9,0)
      sum += parseInt(lastDigit)
      return sum%10 === 0
  }

From 84ab6f1d9f87baa766d9b2578e9f4518990cf505 Mon Sep 17 00:00:00 2001
From: Rohit Tanwar <31792358+kriadmin@users.noreply.github.com>
Date: Wed, 3 Jan 2018 17:56:42 +0530
Subject: [PATCH 3/5] Update luhnCheck.md

---
 snippets/luhnCheck.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/snippets/luhnCheck.md b/snippets/luhnCheck.md
index 4ab440d43..4695a060b 100644
--- a/snippets/luhnCheck.md
+++ b/snippets/luhnCheck.md
@@ -6,7 +6,7 @@ Works with numbers and strings alike
 const luhnCheck = num => { 
     let arr = (num+'').split('').reverse()
     let lastDigit = arr.splice(0,1)
-    let sum = arr.reduce((acc,val,i) =>  (acc,val,i) => i%2!==0 ? acc + parseInt(val) : acc + (parseInt(val) * 2)%9 || 9,0)
+    let sum = arr.reduce((acc,val,i) => i%2!==0 ? acc + parseInt(val) : acc + (parseInt(val) * 2)%9 || 9,0)
      sum += parseInt(lastDigit)
      return sum%10 === 0
  }

From 6e296ca45dfb51979992d1da97f92a1b94d4c2fb Mon Sep 17 00:00:00 2001
From: Angelos Chalaris <chalarangelo@gmail.com>
Date: Thu, 4 Jan 2018 11:22:32 +0200
Subject: [PATCH 4/5] Update luhnCheck.md

---
 snippets/luhnCheck.md | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/snippets/luhnCheck.md b/snippets/luhnCheck.md
index 4695a060b..1903fdf90 100644
--- a/snippets/luhnCheck.md
+++ b/snippets/luhnCheck.md
@@ -1,19 +1,26 @@
 ### luhnCheck
 
 Implementation of the [Luhn Algorithm](https://en.wikipedia.org/wiki/Luhn_algorithm) used to validate a variety of identification numbers, such as credit card numbers, IMEI numbers, National Provider Identifier numbers etc.
-Works with numbers and strings alike
+
+Use `String.split('')`, `Array.reverse()` and `Array.map()` in combination with `parseInt()` to obtain an array of digits.
+Use `Array.splice(0,1)` to obtain the last digit.
+Use `Array.reduce()` to implement the Luhn Algorithm.
+Return `true` if `sum` is divisible by `10`, `false` otherwise.
+
+
 ``` js 
 const luhnCheck = num => { 
-    let arr = (num+'').split('').reverse()
-    let lastDigit = arr.splice(0,1)
-    let sum = arr.reduce((acc,val,i) => i%2!==0 ? acc + parseInt(val) : acc + (parseInt(val) * 2)%9 || 9,0)
-     sum += parseInt(lastDigit)
-     return sum%10 === 0
- }
+  let arr = (num+'').split('').reverse().map(x => parseInt(x));
+  let lastDigit = arr.splice(0,1)[0];
+  let sum = arr.reduce((acc,val,i) => i%2!==0 ? acc + val : acc + (val * 2) % 9 || 9,0);
+  sum += lastDigit;
+  return sum%10 === 0;
+}
 ```
+
 ```js
- luhnCheck("4485275742308327"); //true
- luhnCheck(4485275742308327); //true
- luhnCheck(6011329933655299); // true
- luhnCheck(123456789); //false
+luhnCheck("4485275742308327"); // true
+luhnCheck(4485275742308327); // true
+luhnCheck(6011329933655299); //  true
+luhnCheck(123456789); // false
 ```

From 0e79b52ff63e1d4bce466f9032b0e1dd5c2deb61 Mon Sep 17 00:00:00 2001
From: Angelos Chalaris <chalarangelo@gmail.com>
Date: Thu, 4 Jan 2018 11:23:07 +0200
Subject: [PATCH 5/5] Update luhnCheck.md

---
 snippets/luhnCheck.md | 1 -
 1 file changed, 1 deletion(-)

diff --git a/snippets/luhnCheck.md b/snippets/luhnCheck.md
index 1903fdf90..cbd3918f7 100644
--- a/snippets/luhnCheck.md
+++ b/snippets/luhnCheck.md
@@ -20,7 +20,6 @@ const luhnCheck = num => {
 
 ```js
 luhnCheck("4485275742308327"); // true
-luhnCheck(4485275742308327); // true
 luhnCheck(6011329933655299); //  true
 luhnCheck(123456789); // false
 ```