封装的获取任意月底的函数

封装的获取任意月底的函数

function hqyd(data) {
// 判断是否为闰年的函数
    function isRunYear(year1) {
        var flag = false;
        if (year1 % 4 == 0 && year1 % 100 != 0 || year1 % 400 == 0) {
            flag = true;
        }
        return flag;
    }
    // let y = new Date().getFullYear();
    // let m = new Date().getMonth();
    let y = data.getFullYear();
    let m = data.getMonth() + 1;
    if (m < 10) {
        m = "0" + m;
    }
    if (m == "00") {
        y = y - 1;
        m = 12;
    }
    let result;
  	if (m == "02") {
        if (isRunYear(y)) {
            result = y + "-" + m + "-29";
        } else {
            result = y + "-" + m + "-28";
        }
    }else if (m == "04" || m == "06" || m == "09" || m == 11) {
        result = y + "-" + m + "-30";
    } else {
        result = y + "-" + m + "-31";
    }
    return result;
}

console.log(hqyd(new Date("2024-02-01")))

结果：2024-02-29

console.log(hqyd(new Date("2023-02-01")))

结果：2023-02-28