JS Implementation Calendar can get the specified date weeks and days of the week sample sharing (JS get the day of the Week) _ Basic knowledge

Should be interactive, choose JS to achieve, is also a pair of programming for the preliminary. I'll have the display part written in HTML, click on the button to trigger the event function is check ();

Copy Code code as follows:

function Oncheck () {
var year = document.getElementById ("year"). Value; Gets the text box "year" var theyear =year * 1; Convert to Number type//alert (theyear); Get month value
var month = document.getElementById ("month");
var Index1=month.selectedindex; var themonth = Month.options[index1].value; Get month value
var day = document.getElementById (' Day ');
var Index2=day.selectedindex;
var theday = Day.options[index2].value;

Input Value Judgment section
...
Calling the core function
Days (Theyear,themonth,theday);
}

The core function days are as follows:

Copy Code code as follows:

Function days (year,month,day) {
var days = 0; Change date to day of year
Cumulative month Days
for (var i = 1; i < month; i++) {
switch (i) {
Semi-rotary, plus 31.
Case 1:
Case 3:
Case 5:
Case 7:
Case 8:
Case 10:
Case 12:{
days = 31;
Break
}
The circumstances of the Moon plus 30.
Case 4:
Case 6:
Case 9:
Case 11:{
days = 30;
Break
}
February situation, according to the type of year to add
Case 2:{
if (Isleapyear (year)) {
days = 29; Leap year plus 29
}
else {
days = 28;
}
Break
}
}
}
Day = day * 1;
Days = day; Number of days of the month plus days

var date0 = new Date (year,0,1); The first day of the year is the week
Alert (Date0.getday ());
var date1 = new Date (year,month-1,day); Format Date values, 0-11 represents January-December;
Alert (days + date0.getday () +6)/7);
var nthofweek = Math.floor (days + date0.getday () +6)/7); Rounding down
alert (Nthofweek);
var today = new Array ("Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday");
Day.getday (): 0 of the one weeks returned according to date is Sunday
Alert ("The date is the" +days+ "Day of the Year \ n" + "is the" +nthofweek+ "Week" +today[date1.getday ()]);
}

Many unexpected errors were encountered during debugging, such as the calculation errors caused by type mismatches, such as rounding of numbers;
With the help of his teammates, he is responsible for reviewing and assisting in catching bugs, and I am responsible for implementing and coding;
In the last link, the input value of the test, we are very good mutual assistance, analysis of different input, covering a variety of possible accidents, quickly completed the function of perfection;
The following is the code that determines whether the input value is allowed:

Copy Code code as follows:

if (isNaN (theyear) | | | theyear < 0) {
Alert ("Input is incorrect, please re-enter");
return;
}

if ((Themonth = 2 && theday > && isleapyear (theyear)) | | (Themonth = 2 && theday > &&!isleapyear (theyear)) {
Alert ("Input is incorrect, please re-enter");
return;
}

if (Themonth = = 4 | | themonth = 6 | | | themonth = 9 | | themonth = && Theday = 31) {
Alert ("Input is incorrect, please re-enter");
return;
}