js interceptación de caracteres, interceptación del primero a los pocos caracteres
let sssj = '2019-10-10 10:23:34'
let a = sssj.slice( 0, 10);//截取0到第十个的字符
console.log(a) // 输出为2019-10-10
let sssj = '2019-10-10 10:23:34'
let a = sssj.slice( 0, 10);//截取0到第十个的字符
console.log(a) // 输出为2019-10-10