!!value
Boolean(value)
Number.isNaN(value)
value == null
value === null
typeof(value) == 'undefined'
export function foo() {} export const bar = () => {}; const baz = () => {}; export default baz; export default function baz() {}; // INVALID export default const qux = () => {};
if (/regex/.test(string)) { }
function range(start, end) { return Array.from({ length: end - start + 1 }, (_, i) => start + i) }