How to Generate a Random Letter In JavaScript

To generate a random letter using JavaScript, we can build a custom function that uses the JavaScript random() method along with the charAt() method. Here is our function below to generate a random letter In JavaScript:

function randomLetter() {
  var letters = 'abcdefghijklmnopqrstuvwxyz';
  var randomNum = Math.round(Math.random() * 26);
  var randomLetter = letters.charAt(randomNum);
  return randomLetter;
};

Let’s break down this function line by line.

In our randomLetter() function, we first start out by creating a string that just contains all of the letters of the alphabet.

We next generate a random number between 0 and 26. We do this with the help of the Math.random() and Math.round() methods.

Finally, using the string of letters we created and a random number from 0-26 we generated, we just use the String charAt() method to get the character located at a random spot in the string of letters.

Let’s see this function in action below.

Generating a Random Letter in JavaScript With a Click

To generate a random letter on click using JavaScript, we can combine the function randomLetter() we created above with a click event.

Let’s say we have the following HTML, and we want to give the user the ability to generate a random letter.

<div id="div1">
  <div id="click-me" onclick="randomLetter()">Generate random letter</div>
  <p>Our random letter is: <span id="rand"></span></p>
</div>

We can utilize the onclick event, Math random() method, the Math round() method, and the innerHTML property to change the text of the span.

Below is the JavaScript code which will allow the user to be able to generate a random letter just by clicking a button.

function randomLetter() {
  var letters = 'abcdefghijklmnopqrstuvwxyz';
  var randomNum = Math.round(Math.random() * 26);
  var randomLetter = letters.charAt(randomNum);
  document.getElementById("rand").innerHTML = randomLetter;
};

The final code and output for this example of how to generate a random letter with a click using Javascript is below:

Code Output:

Full Code:

<div id="div1">
  <div id="click-me" onclick="randomLetter()">Generate random letter</div>
  <p>Our random letter is: <span id="rand"></span></p>
</div>

<script>

function randomLetter() {
  var letters = 'abcdefghijklmnopqrstuvwxyz';
  var randomNum = Math.round(Math.random() * 26);
  var randomLetter = letters.charAt(randomNum);
  document.getElementById("rand").innerHTML = randomLetter;
};

</script>

Hopefully this article has been useful for you to understand how to generate a random letter in Javascript.