The program looks like this: first collect the year and month input by the user, obtain the maximum number of days in the month through calculation, and obtain the day of the week that the first day of the month is. Then fill in the table with specific information for that month.
]<script>
function getMonthJuZhen(date){
if(arguments.length == 0){
throw new Error("need a date");
}
if(arguments[0] == null){
throw new Error("date is null or undefined");
}
if(arguments[0] instanceof Date){
var monthjuzhen = new Array(5);
for(var r = 0 ; r < 5 ; r++){
monthjuzhen[r] = [0,0,0,0,0,0,0];
}
var maxDay = getMaxDay(arguments[0]);
arguments[0].setDate(1);
var r = 0;
var c = arguments[0].getDay();
for(var d = 1 ; d <= maxDay ; d++){
monthjuzhen[r][c] = d;
if(c == 6){
if(r == 4){
r = 0;
}
else{
r++;
}
c = 0;
}
else{
c++;
}
}
return monthjuzhen;
}
else{
throw new Error("need a date");
}
}
function getMaxDay(date){
if(arguments.length == 0){
throw new Error("need a date");
}
if(arguments[0] == null){
throw new Error("date is null or undefined");
}
if(arguments[0] instanceof Date){
var tempDate = new Date(arguments[0].toString());
if(arguments[0].getMonth() == 11){
tempDate.setFullYear((tempDate.getFullYear()+1));
tempDate.setMonth(0);
}
else{
tempDate.setMonth((tempDate.getMonth()+1));
}
return Math.floor((tempDate.getTime()-arguments[0].getTime())/(1000*60*60*24));
}
else{
throw new Error("need a date");
}
}
function updateDate(){
var yearInput = document.getElementById("yearinput");
var monthInput = document.getElementById("monthinput");
try{
var year = parseInt(yearInput.value);
var month = parseInt(monthInput.value);
if(isNaN(year)){
if(isNaN(month)){
monthInput.value = "";
}
yearInput.value = "";
return;
}
if(isNaN(month)){
monthInput.value = "";
return;
}
if(month > 12 || month < 1){
monthInput.value = "";
return;
}
month--;
var date = new Date(year,month);
var monthjuzhen = getMonthJuZhen(date);
var day;
var dayvalue;
for(var r in monthjuzhen){
for(var c in monthjuzhen[parseInt(r)]){
day = document.getElementById(r+"-"+c);
dayvalue = monthjuzhen[parseInt(r)][parseInt(c)];
if(dayvalue == 0){
if(day.hasChildNodes()){
day.removeChild(day.firstChild);
}
day.onmouseover = null;
day.onmouseout = null;
day.onclick = null;
continue;
}
if(day.hasChildNodes()){
day.firstChild.nodeValue = dayvalue;
}
else{
day.appendChild(document.createTextNode(dayvalue));
}
day.setAttribute("date",year+"-"+month+"-"+dayvalue);
day.onmouseover = function(){this.style.backgroundColor = "black";this.style.color = "white";};
day.onmouseout = function(){this.style.backgroundColor = "white";this.style.color = "black"};
day.onclick = subDate;
}
}
}
catch(e){
alert(e);
}
}
function subDate(){
var date = this.getAttribute("date").match(/(\d+)-(\d+)-(\d+)/);
alert(new Date(date[1],date[2],date[3]));
}
</script>