js获取当前周、上一周、下一周日期

秒速五厘米 2021-09-16 07:16 1169阅读 0赞

最近在做一个课表的功能，需实现选择了第几周之后，该周相关的日期会自动更改过来，于是就在网上找了资料，经过一下午的折腾，终于把它实现了。

![70][]![70 1][]

虽然是用在小程序中，但js代码都是大同小异的，只需做一些小小的修改。如果你是用在web网页中，那么就不需要怎么修改了，下面我们来看代码。

1、获取当前周、上一周、下一周日期

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html >
    <head>
      <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
      <title>日历操作</title>
      <script>
        window.onload = function(){     
          var cells = document.getElementById('monitor').getElementsByTagName('td');
          var clen = cells.length;
          var currentFirstDate;
          var formatDate = function(date){       
            var year = date.getFullYear()+'年';
            var month = (date.getMonth()+1)+'月';
            var day = date.getDate()+'日';
            var week = '('+['星期天','星期一','星期二','星期三','星期四','星期五','星期六'][date.getDay()]+')'; 
     
            return year+month+day+'  '+week;
          };
    
    
          var addDate= function(date,n){    
            date.setDate(date.getDate()+n);    
            return date;
          };
    
    
          var setDate = function(date){       
            var week = date.getDay()-1;
            date = addDate(date,week*-1);
            currentFirstDate = new Date(date);
     
            for(var i = 0;i<clen;i++){         
              // cells[i].innerHTML = formatDate(i==0 ? date : addDate(date,1));    星期一开始
              cells[i].innerHTML = formatDate(i==0 ? addDate(date,-1) : addDate(date,1));//星期日开始
            }        
          };
    
    
          document.getElementById('last-week').onclick = function(){
            setDate(addDate(currentFirstDate,-7));     
          };       
          document.getElementById('next-week').onclick = function(){         
            setDate(addDate(currentFirstDate,7));
          };   
          setDate(new Date());
    
        }
      </script>
    </head>
    <body>
      <button id="last-week">上一周</button><button id="next-week">下一周</button>
      <table id="monitor">
        <tr>
          <td></td>
          <td></td>
          <td></td>
          <td></td>
          <td></td>
          <td></td>
          <td></td>
        </tr>
      </table>
    </body>
    </html>

2、改造后（点击周数，显示对应周数的日期）

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html >
    <head>
      <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
      <title>js通过给出第几周，获得该周日历（课表日历）</title>
      <script type="text/javascript" src="js/jquery-1.7.1.min.js"></script>
      <script>
        window.onload = function(){     
          var cells = document.getElementById('monitor').getElementsByTagName('td');
          var clen = cells.length;
          var currentFirstDate;
          var formatDate = function(date){       
            var year = date.getFullYear()+'年';
            var month = (date.getMonth()+1)+'月';
            var day = date.getDate()+'日';
            var week = '('+['星期天','星期一','星期二','星期三','星期四','星期五','星期六'][date.getDay()]+')'; 
     
            return year+month+day+'  '+week;
          };
    
    
          var addDate= function(date,n){    
            date.setDate(date.getDate()+n);    
            return date;
          };
    
    
          var setDate = function(date){       
            var week = date.getDay()-1;
            date = addDate(date,week*-1);
            currentFirstDate = new Date(date);
     
            for(var i = 0;i<clen;i++){         
               cells[i].innerHTML = formatDate(i==0 ? date : addDate(date,1));   //星期一开始
              //cells[i].innerHTML = formatDate(i==0 ? addDate(date,-1) : addDate(date,1));   //星期天开始
            }        
          };
    
    
          	var chushi=1;//初始周 第1周
          	//使用each()方法进行循环
    		$("button").each(function(index,element){
    			//这里的index就是当前对象下标，element就是当前对象（dom对象）
    			$(element).click(function(){
    
    				console.log($(this).text());
    				var value=$(this).text();
    
    				//这里的周跟当前周(上一次点击的或初始的)进行比较
    				console.log(value-chushi);
    				var result=value-chushi;
    				if(result>0){
    					setDate(addDate(currentFirstDate,7*result));     
    				}
    				else if(result<0){
    					result= Math.abs(result);  
    					setDate(addDate(currentFirstDate,-(7*result)));
    				}
    				else if(result==0){
    					setDate(addDate(currentFirstDate,0));
    				}
    
    				chushi=$(this).text();
    
    
    			})
    		})
    
    
    
          setDate(new Date());
        }
      </script>
    </head>
    <body>
      
    
      <button class="zhou">1</button>
      <button class="zhou">2</button>
      <button class="zhou">3</button>
      <button class="zhou">4</button>
      <button class="zhou">5</button>
      <button class="zhou">6</button>
      <button class="zhou">7</button>
      <button class="zhou">8</button>
      <button class="zhou">9</button>
      <button class="zhou">10</button>
    
    
      <table id="monitor">
        <tr>
          <td></td>
          <td></td>
          <td></td>
          <td></td>
          <td></td>
          <td></td>
          <td></td>
        </tr>
      </table>
    </body>
    </html>

赶快复制代码看看效果吧，相信你也很快能够实现你的需求的~

[70]: https://img-blog.csdn.net/2018090610023999?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2NzQyNzIw/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70
[70 1]: /images/20210813/69b516da796e46c2b225c0c88968804c.png