Recursion source code & videos added

Author: Vishal-raj-1

README.md

@@ -26,4 +26,5 @@
 - [Time Complexity: Big O notation](https://github.com/Vishal-raj-1/DSA-In-JS-With-Vishal/blob/main/Time%20Complexity/README.md)
 - [Array](https://github.com/Vishal-raj-1/DSA-In-JS-With-Vishal/blob/main/Array/README.md)
 - [Polyfill of Map, Filter & Reduce](https://github.com/Vishal-raj-1/DSA-In-JS-With-Vishal/blob/main/Array/Polyfill.md)
-- [String](https://github.com/Vishal-raj-1/DSA-In-JS-With-Vishal/blob/main/String/README.md)
+- [String](https://github.com/Vishal-raj-1/DSA-In-JS-With-Vishal/blob/main/String/README.md)
+- [Recursion](https://github.com/Vishal-raj-1/DSA-In-JS-With-Vishal/blob/main/Recursion/README.md)

Recursion/README.md

@@ -0,0 +1,56 @@
+# Recursion in JavaScript
+
+<p align="center">
+  <a href="https://youtu.be/5J07qXtAPb4">
+  <img src="https://img.youtube.com/vi/5J07qXtAPb4/0.jpg" alt="Recursion in JavaScript" />
+  </a>
+</p>
+
+### Factorial of a Number
+
+```javascript
+function factorial(n){
+    if(n === 0)
+        return 1;
+    return n * factorial(n - 1);
+}
+
+console.log(factorial(8));
+```
+
+### Sum of Array
+
+```javascript
+function sumOfArrays(arr, n){
+    if(n === 0){
+        return 0;
+    }
+
+    return arr[n - 1] + sumOfArrays(arr, n - 1);
+}
+
+console.log(sumOfArrays([1, 2, 3, 4, 5], 5));
+```
+
+### Fibonacci Number
+
+```javascript
+function fibo(n){
+    if(n < 2){
+        return n;
+    }
+    return fibo(n - 1) + fibo(n - 2);
+}
+
+console.log(fibo(5));
+```
+
+### Practice Questions (solve using recursion):
+
+- Check whether a string is palindrome or not
+- Create pow(x, n) function which returns x^n
+- Create a function which returns the sum of digits of a number (e.g., sumOfDigits(453) is 12)
+- Create a function which returns the number of digits in a number (e.g., countDigits(453) is 3)
+- Create a function to find the LCM of two numbers
+- Create a function to find the GCD of two numbers
+- Create a function to reverse a string