convertion console.log(Number('7'); // 7 console.log(+'7'); // 7 parsing console.log(Number.parseInt('20px')); // 20 console.log(Number.parseInt('e13')); // NaN console.log(Number.parseInt(' 4.5rem ')); // 4 console.log(Number.parseFloat(' 6.5rem ')); // 6.5 .isNaN .isFinite determines whether the passed value is a finite number(유한수) (best way to check if the value is number) con..