js 判断今天昨天

function isTodayOrYesterday(dateString) {
    const inputDate = new Date(dateString);
    const today = new Date();
    const yesterday = new Date();
    yesterday.setDate(today.getDate() - 1);

    // 设置时间部分为00:00:00，以确保只比较日期
    today.setHours(0, 0, 0, 0);
    yesterday.setHours(0, 0, 0, 0);
    inputDate.setHours(0, 0, 0, 0);

    if (inputDate.getTime() === today.getTime()) {
        return '今天';
    } else if (inputDate.getTime() === yesterday.getTime()) {
        return '昨天';
    } else {
        return '既不是今天也不是昨天';
    }
}

// 示例用法
const dateToCheck = '2023-04-25T15:30:00'; // 替换为你要检查的日期字符串
console.log(isTodayOrYesterday(dateToCheck)); // 输出结果