export function getDateString ( ) { const now = new Date ( ) ; const year = now . getFullYear ( ) ; const month = now . getMonth ( ) ; const day = now . getDate ( ) ; const hour = now . getHours ( ) ; const minute = now . getMinutes ( ) ; const second = now . getSeconds ( ) ; return `${ year }-${ month }-${ day }_${ hour }:${ minute }:${ second }` ; }