Keep only first n characters in a string?

const result="Hiya how are you".substring(0,8);
console.log(result);
console.log(result.length);

You are looking for JavaScript’s String method substring

e.g.

'Hiya how are you'.substring(0,8);

Which returns the string starting at the first character and finishing before the 9th character – i.e. ‘Hiya how’.

substring documentation