How to allow only English letters in input fields?

Question

So, this is my input field:

How can I allow only English letters?

This is the RegEx

Answer 1

You could use /[A-Za-z]/ regular expression and an input event handler which is fired every time the value of the element changes. Something like below:

const regex = /[A-Za-z]/;
function validate(e) {
  const chars = e.target.value.split('');
  const char = chars.pop();
  if (!regex.test(char)) {
    e.target.value = chars.join('');
    console.log(`${char} is not a valid character.`);
  }
}
document.querySelector('#myInput').addEventListener('input', validate);

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