此Javascript代码创建月份和年份的日历并将其显示在屏幕上。该代码适用于除Chrome以外的所有浏览器。在Chrome中，lastDate.getDate();会返回Nan为什么？
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>Calendar of Events</title>
<style type="text/css">
#evtcal a:link {font: normal 12pt "Arial", "Helvetica", "Sans Serif"; color: #004400; text-decoration: none;} /* unvisited link */
#evtcal a:visited {font: normal 12pt "Arial", "Helvetica", "Sans Serif"; color: #004400; text-decoration: none;} /* visited link */
#evtcal a:hover {font: normal 12pt "Arial", "Helvetica", "Sans Serif"; color: #004400; text-decoration: underline;} /* mouse over link */
#evtcal a:active {font: normal 12pt "Arial", "Helvetica", "Sans Serif"; color: #004400; text-decoration: none;} /* selected link */
</style>
<script language="JavaScript" type="text/javascript" src="events.js"></script>
<script type="text/JavaScript" language="JavaScript">
/* Preload images script */
var myimages=new Array()
function preloadimages(){
for (i=0;i<preloadimages.arguments.length;i++){
myimages[i]=new Image();
myimages[i].src=preloadimages.arguments[i];
}
}
/* The path of images to be preloaded inside parenthesis: (Extend list as desired.) */
preloadimages("images/PrevYrOff40x40.jpg","images/PrevYrOn40x40.jpg","images/PrevMoOff40x40.jpg","images/PrevMoOn40x40.jpg","images/NextYrOff40x40.jpg","images/NextYrOn40x40.jpg","images/NextMoOff40x40.jpg","images/NextMoOn40x40.jpg");
/***************************************************************************************
JavaScript Calendar - Digital Christian Design
//Script featured on and available at JavaScript Kit: http://www.javascriptkit.com
// Functions
changedate(): Moves to next or previous month or year, or current month depending on the button clicked.
createCalendar(): Renders the calander into the page with links for each to fill the date form filds above.
***************************************************************************************/
var thisDate = 1; // Tracks current date being written in calendar
var wordMonth = new Array("January","February","March","April","May","June","July","August","September","October","November","December");
var today = new Date(); // Date object to store the current date
var todaysDay = today.getDay() + 1; // Stores the current day number 1-7
var todaysDate = today.getDate(); // Stores the current numeric date within the month
var todaysMonth = today.getUTCMonth() + 1; // Stores the current month 1-12
var todaysYear = today.getFullYear(); // Stores the current year
var monthNum = todaysMonth; // Tracks the current month being displayed
var yearNum = todaysYear; // Tracks the current year being displayed
var firstDate = new Date(String(monthNum)+"/1/"+String(yearNum)); // Object Storing the first day of the current month
var firstDay = firstDate.getUTCDay(); // Tracks the day number 1-7 of the first day of the current month
var lastDate = new Date(String(monthNum+1)+"/0/"+String(yearNum)); // Tracks the last date of the current month
var numbDays = 0;
var calendarString = "";
var eastermonth = 0;
var easterday = 0;
function changedate(buttonpressed) {
if (buttonpressed == "prevyr") yearNum--;
else if (buttonpressed == "nextyr") yearNum++;
else if (buttonpressed == "prevmo") monthNum--;
else if (buttonpressed == "nextmo") monthNum++;
else if (buttonpressed == "return") {
monthNum = todaysMonth;
yearNum = todaysYear;
}
if (monthNum == 0) {
monthNum = 12;
yearNum--;
}
else if (monthNum == 13) {
monthNum = 1;
yearNum++
}
lastDate = new Date(String(monthNum+1)+"/0/"+String(yearNum));
numbDays = lastDate.getDate();
firstDate = new Date(String(monthNum)+"/1/"+String(yearNum));
firstDay = firstDate.getDay() + 1;
createCalendar();
return;
}
function easter(year) {
// feed in the year it returns the month and day of Easter using two GLOBAL variables: eastermonth and easterday
var a = year % 19;
var b = Math.floor(year/100);
var c = year % 100;
var d = Math.floor(b/4);
var e = b % 4;
var f = Math.floor((b+8) / 25);
var g = Math.floor((b-f+1) / 3);
var h = (19*a + b - d - g + 15) % 30;
var i = Math.floor(c/4);
var j = c % 4;
var k = (32 + 2*e + 2*i - h - j) % 7;
var m = Math.floor((a + 11*h + 22*k) / 451);
var month = Math.floor((h + k - 7*m + 114) / 31);
var day = ((h + k - 7*m +114) % 31) + 1;
eastermonth = month;
easterday = day;
}
function createCalendar() {
calendarString = '';
var daycounter = 0;
calendarString += '<table width="312" border="1" cellpadding="0" cellspacing="1">';
calendarString += '<tr>';
calendarString += '<td align=\"center\" valign=\"center\" width=\"40\" height=\"40\"><a href=\"#\" onMouseOver=\"document.PrevYr.src=\'images\/PrevYrOn40x40\.jpg\';\" onMouseOut=\"document.PrevYr.src=\'images\/PrevYrOff40x40\.jpg\';\" onClick=\"changedate(\'prevyr\')\"><img name=\"PrevYr\" src=\"images\/PrevYrOff40x40\.jpg\" width=\"40\" height=\"40\" border=\"0\" alt=\"Prev Yr\"\/><\/a><\/td>';
calendarString += '<td align=\"center\" valign=\"center\" width=\"40\" height=\"40\"><a href=\"#\" onMouseOver=\"document.PrevMo.src=\'images\/PrevMoOn40x40\.jpg\';\" onMouseOut=\"document.PrevMo.src=\'images\/PrevMoOff40x40\.jpg\';\" onClick=\"changedate(\'prevmo\')\"><img name=\"PrevMo\" src=\"images\/PrevMoOff40x40\.jpg\" width=\"40\" height=\"40\" border=\"0\" alt=\"Prev Mo\"\/><\/a><\/td>';
calendarString += '<td bgcolor=\"#C8C896\" align=\"center\" valign=\"center\" width=\"128\" height=\"40\" colspan=\"3\"><b>' + wordMonth[monthNum-1] + ' ' + yearNum + '<\/b><\/td>';
calendarString += '<td align=\"center\" valign=\"center\" width=\"40\" height=\"40\"><a href=\"#\" onMouseOver=\"document.NextMo.src=\'images\/NextMoOn40x40\.jpg\';\" onMouseOut=\"document.NextMo.src=\'images\/NextMoOff40x40\.jpg\';\" onClick=\"changedate(\'nextmo\')\"><img name=\"NextMo\" src=\"images\/NextMoOff40x40\.jpg\" width=\"40\" height=\"40\" border=\"0\" alt=\"Next Mo\"\/><\/a><\/td>';
calendarString += '<td align=\"center\" valign=\"center\" width=\"40\" height=\"40\"><a href=\"#\" onMouseOver=\"document.NextYr.src=\'images\/NextYrOn40x40\.jpg\';\" onMouseOut=\"document.NextYr.src=\'images\/NextYrOff40x40\.jpg\';\" onClick=\"changedate(\'nextyr\')\"><img name=\"NextYr\" src=\"images\/NextYrOff40x40\.jpg\" width=\"40\" height=\"40\" border=\"0\" alt=\"Next Yr\"\/><\/a><\/td>';
calendarString += '<\/tr>';
calendarString += '<tr>';
calendarString += '<td bgcolor=\"#DDDDDD\" align=\"center\" valign=\"center\" width=\"40\" height=\"22\">Sun<\/td>';
calendarString += '<td bgcolor=\"#DDDDDD\" align=\"center\" valign=\"center\" width=\"40\" height=\"22\">Mon<\/td>';
calendarString += '<td bgcolor=\"#DDDDDD\" align=\"center\" valign=\"center\" width=\"40\" height=\"22\">Tue<\/td>';
calendarString += '<td bgcolor=\"#DDDDDD\" align=\"center\" valign=\"center\" width=\"40\" height=\"22\">Wed<\/td>';
calendarString += '<td bgcolor=\"#DDDDDD\" align=\"center\" valign=\"center\" width=\"40\" height=\"22\">Thu<\/td>';
calendarString += '<td bgcolor=\"#DDDDDD\" align=\"center\" valign=\"center\" width=\"40\" height=\"22\">Fri<\/td>';
calendarString += '<td bgcolor=\"#DDDDDD\" align=\"center\" valign=\"center\" width=\"40\" height=\"22\">Sat<\/td>';
calendarString += '<\/tr>';
thisDate == 1;
for (var i = 1; i <= 6; i++) {
calendarString += '<tr>';
for (var x = 1; x <= 7; x++) {
daycounter = (thisDate - firstDay)+1;
thisDate++;
if ((daycounter > numbDays) || (daycounter < 1)) {
calendarString += '<td align=\"center\" bgcolor=\"#888888\" height=\"30\" width=\"40\"> <\/td>';
} else {
if (checkevents(daycounter,monthNum,yearNum,i,x) || ((todaysDay == x) && (todaysDate == daycounter) && (todaysMonth == monthNum))){
if ((todaysDay == x) && (todaysDate == daycounter) && (todaysMonth == monthNum)) {
calendarString += '<td align=\"center\" bgcolor=\"#AAFFAA\" height=\"30\" width=\"40\"><a href=\"javascript:showevents(' + daycounter + ',' + monthNum + ',' + yearNum + ',' + i + ',' + x + ')\">' + daycounter + '<\/a><\/td>';
}
else calendarString += '<td align=\"center\" bgcolor=\"#FFFFC8\" height=\"30\" width=\"40\"><a href=\"javascript:showevents(' + daycounter + ',' + monthNum + ',' + yearNum + ',' + i + ',' + x + ')\">' + daycounter + '<\/a><\/td>';
} else {
calendarString += '<td align=\"center\" bgcolor=\"#DDFFFF\" height=\"30\" width=\"40\">' + daycounter + '<\/td>';
}
}
}
calendarString += '<\/tr>';
}
calendarString += '<tr><td colspan=\"7\" nowrap align=\"center\" valign=\"center\" bgcolor=\"#C8C896\" width=\"280\" height=\"22\"><a href=\"javascript:changedate(\'return\')\"><b>Show Current Date<\/b><\/a><\/td><\/tr><\/table>';
var object=document.getElementById('calendar');
object.innerHTML= calendarString;
thisDate = 1;
}
function checkevents(day,month,year,week,dayofweek) {
var numevents = 0;
var floater = 0;
for (var i = 0; i < events.length; i++) {
if (events[i][0] == "W") {
if ((events[i][2] == dayofweek)) numevents++;
}
else if (events[i][0] == "Y") {
if ((events[i][2] == day) && (events[i][1] == month)) numevents++;
}
else if (events[i][0] == "F") {
if ((events[i][1] == 3) && (events[i][2] == 0) && (events[i][3] == 0) ) {
easter(year);
if (easterday == day && eastermonth == month) numevents++;
} else {
floater = floatingholiday(year,events[i][1],events[i][2],events[i][3]);
if ((month == 5) && (events[i][1] == 5) && (events[i][2] == 4) && (events[i][3] == 2)) {
if ((floater + 7 <= 31) && (day == floater + 7)) {
numevents++;
} else if ((floater + 7 > 31) && (day == floater)) numevents++;
} else if ((events[i][1] == month) && (floater == day)) numevents++;
}
}
else if ((events[i][2] == day) && (events[i][1] == month) && (events[i][3] == year)) {
numevents++;
}
}
if (numevents == 0) {
return false;
} else {
return true;
}
}
function showevents(day,month,year,week,dayofweek) {
var theevent = "";
var floater = 0;
for (var i = 0; i < events.length; i++) {
// First we'll process recurring events (if any):
if (events[i][0] != "") {
if (events[i][0] == "D") {
}
if (events[i][0] == "W") {
if ((events[i][2] == dayofweek)) {
theevent += "Events of: \n" + month +'/'+ day +'/'+ year + '\n';
theevent += events[i][6] + '\n';
theevent += 'Start Time: ' + events[i][4] + '\n';
theevent += 'Ending Time: ' + events[i][5] + '\n';
theevent += 'Description: ' + events[i][7] + '\n';
theevent += '\n -------------- \n\n';
document.forms.eventform.eventlist.value = theevent;
}
}
if (events[i][0] == "M") {
}
if (events[i][0] == "Y") {
if ((events[i][2] == day) && (events[i][1] == month)) {
theevent += "Events of: \n" + month +'/'+ day +'/'+ year + '\n';
theevent += events[i][6] + '\n';
theevent += 'Start Time: ' + events[i][4] + '\n';
theevent += 'Ending Time: ' + events[i][5] + '\n';
theevent += 'Description: ' + events[i][7] + '\n';
theevent += '\n -------------- \n\n';
document.forms.eventform.eventlist.value = theevent;
}
}
if (events[i][0] == "F") {
if ((events[i][1] == 3) && (events[i][2] == 0) && (events[i][3] == 0) ) {
if (easterday == day && eastermonth == month) {
theevent += "Events of: \n" + month +'/'+ day +'/'+ year + '\n';
theevent += events[i][6] + '\n';
theevent += 'Start Time: ' + events[i][4] + '\n';
theevent += 'Ending Time: ' + events[i][5] + '\n';
theevent += 'Description: ' + events[i][7] + '\n';
theevent += '\n -------------- \n\n';
document.forms.eventform.eventlist.value = theevent;
}
} else {
floater = floatingholiday(year,events[i][1],events[i][2],events[i][3]);
if ((month == 5) && (events[i][1] == 5) && (events[i][2] == 4) && (events[i][3] == 2)) {
if ((floater + 7 <= 31) && (day == floater + 7)) {
theevent += "Events of: \n" + month +'/'+ day +'/'+ year + '\n';
theevent += events[i][6] + '\n';
theevent += 'Start Time: ' + events[i][4] + '\n';
theevent += 'Ending Time: ' + events[i][5] + '\n';
theevent += 'Description: ' + events[i][7] + '\n';
theevent += '\n -------------- \n\n';
document.forms.eventform.eventlist.value = theevent;
} else if ((floater + 7 > 31) && (day == floater)) {
theevent += "Events of: \n" + month +'/'+ day +'/'+ year + '\n';
theevent += events[i][6] + '\n';
theevent += 'Start Time: ' + events[i][4] + '\n';
theevent += 'Ending Time: ' + events[i][5] + '\n';
theevent += 'Description: ' + events[i][7] + '\n';
theevent += '\n -------------- \n\n';
document.forms.eventform.eventlist.value = theevent;
}
} else if ((events[i][1] == month) && (floater == day)) {
theevent += "Events of: \n" + month +'/'+ day +'/'+ year + '\n';
theevent += events[i][6] + '\n';
theevent += 'Start Time: ' + events[i][4] + '\n';
theevent += 'Ending Time: ' + events[i][5] + '\n';
theevent += 'Description: ' + events[i][7] + '\n';
theevent += '\n -------------- \n\n';
document.forms.eventform.eventlist.value = theevent;
}
}
}
}
// Now we'll process any One Time events happening on the matching month, day, year:
else if ((events[i][2] == day) && (events[i][1] == month) && (events[i][3] == year)) {
theevent += "Events of: \n" + month +'/'+ day +'/'+ year + '\n';
theevent += events[i][6] + '\n';
theevent += 'Start Time: ' + events[i][4] + '\n';
theevent += 'Ending Time: ' + events[i][5] + '\n';
theevent += 'Description: ' + events[i][7] + '\n';
theevent += '\n -------------- \n\n';
document.forms.eventform.eventlist.value = theevent;
}
}
if (theevent == "") document.forms.eventform.eventlist.value = 'No events to show.';
}
function floatingholiday(targetyr,targetmo,cardinaloccurrence,targetday) {
// Floating holidays/events of the events.js file uses:
// the Month field for the Month (here it becomes the targetmo field)
// the Day field as the Cardinal Occurrence (here it becomes the cardinaloccurrence field)
// 1=1st, 2=2nd, 3=3rd, 4=4th, 5=5th, 6=6th occurrence of the day listed next
// the Year field as the Day of the week the event/holiday falls on (here it becomes the targetday field)
// 1=Sunday, 2=Monday, 3=Tuesday, 4=Wednesday, 5=Thurday, 6=Friday, 7=Saturday
// example: "F", "1", "3", "2", = Floating holiday in January on the 3rd Monday of that month.
//
// In our code below:
// targetyr is the active year
// targetmo is the active month (1-12)
// cardinaloccurrence is the xth occurrence of the targetday (1-6)
// targetday is the day of the week the floating holiday is on
// 0=Sun; 1=Mon; 2=Tue; 3=Wed; 4=Thu; 5=Fri; 6=Sat
// Note: subtract 1 from the targetday field if the info comes from the events.js file
//
// Note:
// If Memorial Day falls on the 22nd, 23rd, or 24th, then we add 7 to the dayofmonth to the result.
//
// Example: targetyr = 2052; targetmo = 5; cardinaloccurrence = 4; targetday = 1
// This is the same as saying our floating holiday in the year 2052, is during May, on the 4th Monday
//
var firstdate = new Date(String(targetmo)+"/1/"+String(targetyr)); // Object Storing the first day of the current month.
var firstday = firstdate.getUTCDay(); // The first day (0-6) of the target month.
var dayofmonth = 0; // zero out our calendar day variable.
targetday = targetday - 1;
if (targetday >= firstday) {
cardinaloccurrence--; // Subtract 1 from cardinal day.
dayofmonth = (cardinaloccurrence * 7) + ((targetday - firstday)+1);
} else {
dayofmonth = (cardinaloccurrence * 7) + ((targetday - firstday)+1);
}
return dayofmonth;
}
</script>
</head>
<body style="background-color: transparent;" onload="changedate('return')">
<p align="center">Calendar of Events</p>
<center>
<table id="evtcal" border="0" cellpadding="0" cellspacing="0" width="584">
<tbody>
<tr>
<td style="padding: 3px;" align="center" bgcolor="#aaddff" valign="top" width="314">
<div id="calendar"><!-- Dynamically Filled --></div>
You can move to a different month or year by clicking on the buttons or return to today's date by clicking "Show Current Date".</td>
<td width="10"> </td>
<td style="padding: 3px;" align="center" bgcolor="#ffffc8" valign="top" width="260"><b>Intructions:</b><br />Click a highlighted date on the calendar to see a list of events on that day in the box below.<br /><br />
<center><b><u>Events</u></b>
<form id="eventform" name="eventform" action="#" method="get">
<textarea name="eventlist" cols="25" rows="11" wrap="soft">Auto filled when clicking on date.</textarea>
</form>
</center>
</td>
</tr>
</tbody>
</table>
</center>
<br />
<p style="font: normal 11px Arial" align="center">This free script provided by<br />
<a href="http://www.javascriptkit.com">JavaScript Kit</a></p>
</body>
</html>
答案 0 :(得分：1)
使用您当前的逻辑，您将最终得到MonthNum = 13（这将引发错误）
你有：
var todaysMonth = today.getUTCMonth() + 1; // which will be = 12
var monthNum = todaysMonth; // so monthNum = 12
然后你有了这个
var lastDate = new Date(String(monthNum+1)+"/0/"+String(yearNum));
会给你新的日期（“13/0/2015”）
你有一个无效的MONTH（13）和DAY