장점
const buttonClass = `btn ${isPrimary ? 'btn-primary' : ''} ${isLarge ? 'btn-large' : ''}`;
const buttonClass = classNames('btn', {
'btn-primary': isPrimary,
'btn-large': isLarge,
});
const buttonClass = classNames('btn', {
'btn-primary': isPrimary && !isDisabled,
'btn-disabled': isDisabled,
});
const buttonClass = classNames('btn', undefined, false, 'btn-primary');
// 결과: 'btn btn-primary'