Check if a string contains only letters and numbers

const isAlphanumeric = (str) => /^[0-9A-Z]+$/i.test(str);

const isAlphanumeric = (str: string): boolean => /^[0-9A-Z]+$/i.test(str);

isAlphanumeric('helloworld'); // true
isAlphanumeric('HelloWorld'); // true
isAlphanumeric('hello world'); // false
isAlphanumeric('hello123'); // true
isAlphanumeric('hello 123'); // false