根据当前时间获取上一个月的时间

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<head>
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    <title>根据当前时间推算出前n个月的时间/指定月份</title>
</head>
<body>
    <script>
        var m = 1;  //月份 (往前推几个月)
        //月份必须转换为一个数字
        if(parseInt(m) > 0){
            var myDate = new Date();
            var year = myDate.getFullYear(); //年
            var month = myDate.getMonth()+1; //月
            var day = myDate.getDate() //日
//          var day = myDate.getDate() > 10 ? myDate.getDate() : '0' + myDate.getDate();//补零
            var lowDate = ''
            
            // ------------可忽略---------------
            var ylow = parseInt(parseInt(m)/12);//往前推的总月份换成对应的年数取整
            var mlow = parseInt(m) % 12; //往前推的月数
            if(ylow > 0){
                year = year - ylow;
            }else{
                year = year
            }
            // ------------可忽略--------------
            //如果推的月份大于当前的 年份就减一
            if((mlow > month) || (mlow == month)){
                year = year - 1;
                month = 12 - mlow + month;
                lowDate = year + '年' + month + '月' + day + '日'
            }else{
                month = month - mlow;
                lowDate = year + '年' + month + '月' + day + '日'
            }
            console.log(lowDate)
        }else{
            console.log(m)
        }
    </script>
</body>
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转载自www.cnblogs.com/a-pupil/p/10827351.html