if value is a letter javascript code example
Example 1: js is letter
/^[a-z]+$/i.test(nom)
Example 2: check if something is a letter in js
string.charAt(1).toUpperCase() !== string.charAt(1).toLowerCase()
/^[a-z]+$/i.test(nom)
string.charAt(1).toUpperCase() !== string.charAt(1).toLowerCase()