js date 格式转化

function formatDate(date, format) {
    const map = {
        'M': date.getMonth() + 1, // 月份从 0 开始
        'd': date.getDate(),
        'h': date.getHours(),
        'm': date.getMinutes(),
        's': date.getSeconds(),
        'q': Math.floor((date.getMonth() + 3) / 3), // 季度
        'S': date.getMilliseconds() // 毫秒
    };
    format = format.replace(/([yMdhmsqS])+/g, (all, t) => {
        let v = map[t];
        if (v !== undefined) {
            if (all.length > 1) {
                v = '0' + v;
                v = v.substr(v.length - 2);
            }
            return v;
        } else if (t === 'y') {
            return (date.getFullYear() + '').substr(4 - all.length);
        }
        return all;
    });
    return format;
}

const date = new Date();
console.log(formatDate(date, 'YYYY-MM-DD')); // 输出类似 2023-04-10
console.log(formatDate(date, 'MM/DD/YYYY')); // 输出类似 04/10/2023

function parseDate(dateStr, format) {
    const parts = dateStr.match(/(\d+)/g);
    const formatParts = format.match(/([yMdhmsqS])/g);
    const map = {
        'M': 1,
        'd': 2,
        'h': 3,
        'm': 4,
        's': 5,
        'q': 6,
        'S': 7
    };
    const dateObj = new Date();
    for (let i = 0; i < formatParts.length; i++) {
        const part = formatParts[i];
        const value = parseInt(parts[i], 10);
        switch (part) {
            case 'y':
                dateObj.setFullYear(value);
                break;
            case 'M':
                dateObj.setMonth(value - 1);
                break;
            case 'd':
                dateObj.setDate(value);
                break;
            case 'h':
                dateObj.setHours(value);
                break;
            case 'm':
                dateObj.setMinutes(value);
                break;
            case 's':
                dateObj.setSeconds(value);
                break;
            case 'q':
                dateObj.setMonth((value - 1) * 3);
                break;
            case 'S':
                dateObj.setMilliseconds(value);
                break;
        }
    }
    return dateObj;
}

const dateStr = '2023-04-10';
const dateObj = parseDate(dateStr, 'YYYY-MM-DD');
console.log(dateObj); // 输出类似 Tue Apr 10 2023 00:00:00 GMT+0800 (中国标准时间)

if (isNaN(date.getTime())) {
    console.error('Invalid date object');
    return;
}

const regex = /^\d{4}-\d{2}-\d{2}$/;
if (!regex.test(dateStr)) {
    console.error('Invalid date string format');
    return;
}