JavaScript - Generate Random Unique Number

In this tutorial we will create a Generate Random Unique Number using JavaScript. This code will generate random unique numbers when the user click the button. The code itself use onclick() call a specific method that will randomize the giver number using Math.floor to loop the order of numbers being display. This code is free to use, you can modify it as your own, We will be using JavaScript as a server-side scripting language because It allows greater control of your web page behavior than HTML alone. It is embedded in HTML that responsible to allow user to interact with the computer .

Getting started:

First you have to download bootstrap framework, this is the link for the bootstrap that I used for the layout design https://getbootstrap.com/.

The Main Interface

This code contains the interface of the application. To create this just write these block of code inside the text editor and save this as index.html.
  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <meta charset="UTF-8" name="viewport" content="width=device-width, initial-scale=1" />
  5. <link rel="stylesheet" type="text/css" href="css/bootstrap.css" />
  6. </head>
  7. <nav class="navbar navbar-default">
  8. <div class="container-fluid">
  9. <a class="navbar-brand" href="https://sourcecodester.com">Sourcecodester</a>
  10. </div>
  11. </nav>
  12. <div class="col-md-3"></div>
  13. <div class="col-md-6 well">
  14. <h3 class="text-primary">JavaScript - Generate Random Unique Number</h3>
  15. <hr style="border-top:1px dotted #ccc;"/>
  16. <div class="col-md-5">
  17. <h6>Note:</h6>
  18. <h6>The Range of number is between 1 - 65</h6>
  19. <button class="btn btn-primary btn-block" onclick="rollNumber();">Roll A Number</button>
  20. </div>
  21. <div class="col-md-7">
  22. <h1>Jackpot Numbers:</h1>
  23. <div id="result"></div>
  24. </div>
  25. </div>
  26. <script src="js/script.js"></script>
  27. </body>
  28. </html>

Creating the Script

This code contains the script of the application. This code will generate unique numbers when the button is clicked. To do this just copy and write these block of codes inside the text editor, then save it as script.js inside the js folder.
  1. function rollNumber(){
  2. var set = [];
  3. while(set.length < 6){
  4. var r = Math.floor(Math.random() * 65) + 1;
  5. if(set.indexOf(r) === -1) set.push(r);
  6. }
  7.  
  8. displayResult(set);
  9. }
  10.  
  11.  
  12. function displayResult(set){
  13. set.join(", ");
  14.  
  15. document.getElementById('result').innerHTML="<center><h1 class='text-success'>"+set+"</h1></center>";
  16. }
There you have it we successfully created a Generate Random Unique Number using JavaScript. I hope that this simple tutorial help you to what you are looking for. For more updates and tutorials just kindly visit this site. Enjoy Coding!

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