Question

我建立了这一小段代码（在许多SO线程的帮助下），它在过去两年中运行良好，但在2018年它错误地解释了第一周。

function getDateOutWeek(week, year, lastDay) {
    var d = new Date(year, 0, 1 + (week) * 7);
    var day = d.getDay();
    var firstDay = d.getDate() - day + (day === 0 ? -6 : 1); // adjust when day is sunday

    if (!lastDay) {
        alert(new Date(d.setDate(firstDay)).toDateString());
    } else {
        alert(new Date(d.setDate(firstDay + 6)).toDateString());
    }

}

getDateOutWeek("1", "2018");

它返回08.01.2018但应该返回01.01.2018。它出现在第一行calculate 1 + (week) * 7 = 8。我无法弄清楚如何在这里得到正确的值。

Answer 1

为什么你一周加1？以下代码工作正常

function getDateOutWeek(week, year, lastDay) {
    var d = new Date(year, 0, week* 7);
    var day = d.getDay();
    var firstDay = d.getDate() - day + (day === 0 ? -6 : 1); // adjust when day is sunday

    if (!lastDay) {
        alert(new Date(d.setDate(firstDay)).toDateString());
    } else {
        alert(new Date(d.setDate(firstDay + 6)).toDateString());
    }

}

getDateOutWeek("1", "2018")

JS Date of the Week

1 个答案: