Category: JavaScript

Sometimes, we want to use a regex to add a space after each comma in JavaScript.

In this article, we’ll look at how to use a regex to add a space after each comma in JavaScript.

How to use a regex to add a space after each comma in JavaScript?

To use a regex to add a space after each comma in JavaScript, we can use the string replace method.

For instance, we write:

const input = '1,2,3,4,5'
const output = input.replace(/(\d+,)/g, '$1 ');
console.log(output)

to call input.replace with a regex that matches all instances of digits with a comma after it.

Then we replace matches with a extra space with '$1 '.

Therefore, output is '1, 2, 3, 4, 5'.

Conclusion

To use a regex to add a space after each comma in JavaScript, we can use the string replace method.

Sometimes, we want to confirm before a form submit with JavaScript.

In this article, we’ll look at how to confirm before a form submit with JavaScript.

How to confirm before a form submit with JavaScript?

To confirm before a form submit with JavaScript, we can call the confirm function.

For instance, we write:

<form>
  <input>
  <input type="submit" />
</form>

to add a form.

Then we write:

const form = document.querySelector('form')
form.onsubmit = (e) => {
  e.preventDefault()
  const confirmSubmit = confirm('Are you sure you want to submit this form?');
  if (confirmSubmit) {
    console.log('submitted')
  }
}

to select a form with querySelector.

And then we set form.onsubmit to a function that calls confirm to check show a prompt to let the user confirm whether they want to submit the form or not.

If confirmSubmit is true, then user clicked OK and we move forward with submitting the form.

Conclusion

To confirm before a form submit with JavaScript, we can call the confirm function.

Sometimes, we want to clone a file input element in JavaScript.

In this article, we’ll look at how to clone a file input element in JavaScript.

How to clone a file input element in JavaScript?

To clone a file input element in JavaScript, we can use the cloneNode method.

For instance, we write:

<input type='file'>

to add a file input.

Then we write:

const input = document.querySelector('input')
const inputClone = input.cloneNode(true)
document.body.appendChild(inputClone)

to select the file input with querySelector.

Then we call input.cloneNode with true to do a deep clone of the input and return it.

Finally, we call document.body.appendChild with inputClone to append it as a child of the body element.

Conclusion

To clone a file input element in JavaScript, we can use the cloneNode method.

Sometimes, we want to check for the subtract key press with JavaScript.

In this article, we’ll look at how to check for the subtract key press with JavaScript.

How to check for the subtract key press with JavaScript?

To check for the subtract key press with JavaScript, we can listen to the keypress event and use the event key property to check which key is pressed.

For instance, we write:

window.onkeypress = (e) => {
  if (e.key === '-') {
    console.log('subtract pressed')
  }
}

to check if the subtract key is pressed with e.key === '-' in the window.

If it’s pressed, then we log 'subtract pressed'.

Conclusion

To check for the subtract key press with JavaScript, we can listen to the keypress event and use the event key property to check which key is pressed.