Learn how to convert a list into an array in JavaScript

🚨 Real-world use-case: I wanted to convert an excel list into an array; it had 200+ records, so a pain to do manually.

So why not create something easy in JavaScript!

The end goal is to have a text area where we can input our list and auto-convert it into an array.

This is going to be the result in Codepen:

See the Pen Learn how to convert a list into an array in JavaScript by Chris Bongers (@rebelchris) on CodePen.

HTML Structure permalink

The HTML will be super easy for this. We just need a textarea and a paragraph to output our array.

<div class="container">
  <textarea id="textarea">
Paste
your 
list 
here</textarea
  >
  <p id="array">["Paste","your ","list ","here"]</p>
</div>

CSS Styling permalink

Let’s also add some super easy CSS to make it look good:

.container {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  flex-direction: column;
  background: #3a86ff;
}
textarea {
  padding: 10px;
  min-width: 200px;
  width: 50vw;
  height: 100px;
  margin-bottom: 10px;
  border-radius: 10px;
}
#array {
  background: #efefef;
  border: 1px dashed #333;
  padding: 10px;
  width: 50vw;
  min-width: 200px;
  word-wrap: break-word;
  margin-bottom: 10px;
  color: #ff006e;
  border-radius: 10px;
}

JavaScript convert a list into an array permalink

Ok, on to the magic part, let’s convert our array input into an array.

We start by adding defining our variables.

const textarea = document.getElementById('textarea');
const array = document.getElementById('array');

Now we can add our input listener to the textarea element.

textarea.addEventListener('input', function () {
  const arrayValues = textarea.value.split(/\n/g);
  array.innerHTML = JSON.stringify(arrayValues);
});

And then, for some magic, we will add a click event to our paragraph, which will auto-select all text.

array.addEventListener('click', function () {
  const range = document.createRange();
  const selection = window.getSelection();
  range.selectNodeContents(array);
  selection.removeAllRanges();
  selection.addRange(range);
});

An awesome, simple tool, but effective!

Thank you for reading, and let’s connect! permalink

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