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JavaScript JavaScript Basics (Retired) Creating Reusable Code with Functions Random Number Challenge, Part II Solution

Daniel LittleThunder
Daniel LittleThunder
6,975 Points
Posted by Daniel LittleThunder
Daniel LittleThunder
6,975 Points

My Random Number Challenge Part II Solution

Hey there everyone. I just wanted to share my solution to the Random Number Challenge Part II. It's not really what was required of the task, but I went ahead and used all of the skills from the previous videos to create a function that accepts 2 arguments for the parameters based on user input.

This solution uses numeric data provided by user input as the arguments for the function. I employed the prompts, alerts, loops, parseInt, and several variable uses, and functions. Below is the code. I hope it helps others see what could be done and how to accept user input with this particular function.

The HTML:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <link rel="stylesheet" href="css/main.css">
  <title>Let's Make a Function</title>
 </head>
<body>
  <div class="container">
  <!--<h1>Let's Make a Function</h1>-->
  <div id="start">

  </div>
   <script src="random.js"></script>
  </div>
</body>
</html>

The JS:

//Sets up function with 2 parameters to return random number based on 2 arguments
function returnRandNum(upper, lower) {
  if (isNaN(upper) || isNaN(lower)) {
    throw new Error("Slow your horses! One of these values is not a number!");
  } else {
    return Math.floor(Math.random() * (upper - lower + 1)) + lower;
  }
}
//Sets up prompts and alerts as function which can be called by button
function playGame() {
//Prompts user for upper numeric input
var upNum = parseInt(Math.round(prompt('Okay! To start, please enter any number greater than 0.')));
//Prompts user for numeric input while input isNaN && <= 0
while (isNaN(upNum) || upNum <= 0) {
  var entNum = prompt("I'm sorry, but you must enter a number which is greater than 0.");
  upNum = parseInt(entNum);
}
//Prompts user for lower numeric input
var lowNum = parseInt(Math.round(prompt('Awesome! Now enter any number greater or less than the previously entered number. The number you enter must also be greater than 0.')));
//Prompts user for numeric input while input isNaN && <=0 && === previous input
while (isNaN(lowNum) || lowNum <= 0 || lowNum === upNum) {
  var entNum = prompt("I'm sorr, but you must enter a number which is greater than 0, and greater or less than your previous number.");
  lowNum = parseInt(entNum);
}
//Alerts user of next step
alert("Great! You entered " + upNum + " and " + lowNum + ". Now we're going to generate a random number between the two numbers you chose. Let's go!")
//Alerts user of random number
var message = "Your random number between " + upNum + " and " + lowNum + " is ";
message += returnRandNum(upNum, lowNum) + "!";
alert(message);
}

//Creates button for starting game
//Calls <div> element with id="start" from index.html
document.getElementById("start").innerHTML = `
<h1>LET'S GUESS SOME NUMBERS!</h1>
<div>
  <button onclick="playGame()">Play</button>
</div>
`;

1 Answer