//代码 2022-11-10 重写
function showDate(str) {
    if (str == '/Date(-62135596800000)/') return '';
    var date = eval('new ' + str.substr(1, str.length - 2)); //new Date()
	Y = date.getFullYear() + '-';
  M = (date.getMonth() + 1 < 10 ? '0' + (date.getMonth() + 1) : date.getMonth()    + 1) + '-';
  D = (date.getDate() < 10 ? '0' + (date.getDate()) : date.getDate()) + ' ';
  h = (date.getHours() < 10 ? '0' + (date.getHours()) : date.getHours()) + ':';
  m = (date.getMinutes() < 10 ? '0' + (date.getMinutes()) : date.getMinutes()) + ':';
  s = (date.getSeconds() < 10 ? '0' + (date.getSeconds()) : date.getSeconds()); 
    return Y + M + D + h + m + s;
}

如：/Date(1642563573347)/
 
调用：
showDate('/Date(1642563573347)/')
 
结果：
2022-01-19 11:39:33