diff --git a/README.md b/README.md
index bdfb40b..dcd01f3 100644
--- a/README.md
+++ b/README.md
@@ -47,10 +47,10 @@
 |41 | [How to convert an array of key-value tuples into an object](#How-to-convert-an-array-of-key-value-tuples-into-an-object)|
 |42 | [Native text to speech JS](#Native-text-to-speech-JS)|
 |43 | [toFixed](#toFixed)|
-
-
-
-
+|44 | [generate randomUUID](#generate-random-uuid)|
+|45 | [structuredClone](#structuredClone)|
+|46 | [get device orientation](#get-device-orientation)|
+|47 | [CONST vs LET vs VAR](#const-let-var)|
 
 **[⬆ Back to Top](#table-of-contents)**
 ### How to generate a random number in a given range
@@ -939,3 +939,69 @@ Warning: Floating point numbers cannot represent all decimals precisely in binar
 2.65.toFixed(1)        // Returns '2.6'. Note it rounds down -why??? see the warning above
 
 ```
+
+
+**[⬆ Back to Top](#table-of-contents)**
+### generate random uuid
+
+The randomUUID() method of the Crypto interface is used to generate a v4 UUID using a cryptographically secure random number generator.
+
+```javascript
+
+crypto.randomUUID() // print in console '460ff1e6-2106-4848-833d-5c5b3bfdc943'
+
+crypto.randomUUID() // print in console '9a91c014-d1b1-453a-8091-ef8b9b48b14a'
+
+
+```
+
+
+**[⬆ Back to Top](#table-of-contents)**
+### structuredClone
+
+If you want to deep clone a value in Node.js, you no longer need to use a library or the JSON.parse(JSON.stringify(value)) hack. You can use the new global function structuredClone()
+
+```javascript
+
+const user = {
+  name: "JS Snippets",
+  address: { street: "Original Road", city: "Placeshire" },
+};
+
+const clonedUser = structuredClone(user);
+
+clonedUser.address.street = "New Road";
+
+console.log("user.address.street:", user.address.street);
+// > Original Road
+
+console.log("clonedUser.address.street:", clonedUser.address.street);
+// > New Road
+
+
+```
+
+**[⬆ Back to Top](#table-of-contents)**
+### get device orientation
+
+Browsers expose a global variable named screen, which we’ll use to access the information we need.
+
+```javascript
+
+function getOrientation() {  
+    const isPortrait = screen.orientation.type.startswith('portrait')  
+    return isPortrait ? 'portrait' : 'landscape'
+}
+
+```
+
+**[⬆ Back to Top](#table-of-contents)**
+### CONST vs LET vs VAR
+
+|                        | const | Let | Var |
+|------------------------|-------|-----|-----|
+| Can be Reaasigned?     | :x:     | :white_check_mark:   |:white_check_mark:   |
+| Cab be Redeclared?     | :x:    | :x:  | :white_check_mark:  |
+| Block Scope            | :white_check_mark:    |:white_check_mark:   | :x:   |
+| Function Scope         | :white_check_mark:     | :white_check_mark:   | :white_check_mark:   |
+| Stored in Global Scope | :x:     | :x:   | :white_check_mark:   |