js 时间戳转换成时间格式，可自定义格式

function formatDate(obj) {
            var timestamp = obj;
            timestamp = timestamp.replace(/^\s+|\s+$/, ‘‘);
            if (/^\d{10}$/.test(timestamp)) {
                timestamp *= 1000;
            } else if (/^\d{13}$/.test(timestamp)) {
                timestamp = parseInt(timestamp);
            } else {
                return "";
            }
            var YmdHis = format(timestamp);
            return YmdHis;
        }

        function format(timestamp) {
            var time = new Date(timestamp);
            var year = time.getFullYear();
            var month = (time.getMonth() + 1) > 9 && (time.getMonth() + 1) || (‘0‘ + (time.getMonth() + 1))
            var date = time.getDate() > 9 && time.getDate() || (‘0‘ + time.getDate())
            var hour = time.getHours() > 9 && time.getHours() || (‘0‘ + time.getHours())
            var minute = time.getMinutes() > 9 && time.getMinutes() || (‘0‘ + time.getMinutes())
            var second = time.getSeconds() > 9 && time.getSeconds() || (‘0‘ + time.getSeconds())
            var YmdHis = year + ‘/‘ + month + ‘/‘ + date + ‘ ‘ + hour + ‘:‘ + minute + ‘:‘ + second;
            return YmdHis;
        }