Check if alphanumeric.
// Using RegEx.
function isAlphanumeric(char: string): boolean {
const alphanumericRegex = /^[a-zA-Z0-9]$/;
return alphanumericRegex.test(char);
}
// Using Unicode Character Codes.
function isAlphanumeric(char: string): boolean {
const charCode = char.charCodeAt(0);
// Check numbers, u-case letters, l-case letters
return (
(charCode >= 48 && charCode <= 57) ||
(charCode >= 65 && charCode <= 90) ||
(charCode >= 97 && charCode <= 122)
);
}