JS實現上一週和下一週
阿新 • • 發佈：2019-02-08
<script> var currDT; var aryDay = new Array("日","一","二","三","四","五","六"); //初始頁面 function ini() { currDT = new Date(); showDate(); } //上一週 或 下一週 function addWeek(ope) { var num = 0; if(ope=="-") { num = -7; } else if(ope=="+") { num = 7; } currDT = addDate(currDT,num); showDate(); } function showDate() { span1.innerHTML = currDT.toLocaleDateString(); //顯示日期 var dw = currDT.getDay(); var tdDT; //確定週一是那天 if(dw==0) { tdDT = addDate(currDT,-6); } else { tdDT = addDate(currDT,(1-dw)); } //在表格中顯示一週的日期 var objTB = document.getElementById("tb1"); for(var i=0;i<7;i++) { if(tdDT.toLocaleDateString()==currDT.toLocaleDateString()) { objTB.rows[0].cells[i].style.color = "red"; //currDT突出顯示 } dw = tdDT.getDay(); objTB.rows[0].cells[i].innerHTML = tdDT.getMonth()+1 + "月" + tdDT.getDate() + "日 星期" + aryDay[dw]; tdDT = addDate(tdDT,1); //下一天 } } //增加或減少若干天，由 num 的正負決定，正為加，負為減 function addDate(dt,num) { var ope = "+"; if(num<0) { ope = "-"; } var reDT = dt; for(var i=0;i<Math.abs(num);i++) { reDT = addOneDay(reDT,ope); } return reDT; } //增加或減少一天，由ope決定, + 為加，- 為減，否則不動 function addOneDay(dt,ope) { var num = 0; if(ope=="-") { num = -1; } else if(ope=="+") { num = 1; } var y = dt.getYear(); var m = dt.getMonth(); var lastDay = getLastDay(y,m); var d = dt.getDate(); d += num; if(d<1) { m--; if(m<0) { y--; m = 11; } d = getLastDay(y,m); } else if(d>lastDay) { m++; if(m>11) { y++; m = 0; } d = 1; } var reDT = new Date(); reDT.setYear(y); reDT.setMonth(m); reDT.setDate(d); return reDT; } //是否為閏年 function isLeapYear(y) { var isLeap = false; if(y%4==0 && y%100!=0 || y%400==0) { isLeap = true; } return isLeap; } //每月最後一天 function getLastDay(y,m) { var lastDay = 28; m++; if(m==1 || m==3 || m==5 || m==7 || m==8 || m==10 || m==12) { lastDay = 31; } else if(m==4 || m==6 || m==9 || m==11) { lastDay = 30; } else if(isLeapYear(y)==true) { lastDay = 29; } return lastDay; } </script>
<body onload="ini()"> <!--載入時初始頁面--> <span style="cursor:hand;font-weight:bold;" onclick="addWeek('-')" title="上一週">←</span> <span id="span1"></span> <span style="cursor:hand;font-weight:bold;" onclick="addWeek('+')" title="下一週">→</span> <br /> <table id="tb1" border="1" style="font-size:10pt"> <tr> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> </tr> </table>