实战
(1)案例描述:随机生成某产品一年中每天的销售额,并计算某一月日平均销售额以及某一周日平均销售额。
(2)实现思路:
1)假设该产品日销售额区间为(0,10000),运用Math对象的random()方法随机生成区间内的随机数;
2)创建三维数组month用于存放每个月每一周每一天的日销售额数据。
<html> <head> <title>计算产品销售额</title> </head> <script> var WeekSales = function() { this.month=[]; this.init = init; this.getAverageSomeMonth = getAverageSomeMonth; this.getAverageSomeWeek = getAverageSomeWeek; }; var init=function(month) { var i=0;j=0;k=0; for(i=0;i<month;i++) { this.month[i] = []; for(k=0;k<4;k++) { this.month[i][k]=[]; for(j=0;j<7;j++) { this.month[i][k][j]=parseInt(Math.random()*10000); } } } }; function getAverageSomeMonth(month) { month = month || 12; console.log(month+"月的日平均销售额:"+this.month[month-1].map(function(arr) {return arr.reduce(function (a,b){return a+b;}); }).reduce(function(a,b){return a+b;})/28) } function getAverageSomeWeek(month,week) { month = month || 12; week = week||1; console.log(month+"月第"+week+"周的日平均销售额:"+ this.month[month-1][week-1].reduce(function(a,b){return a+b;})/7); } var newWeekSales = new WeekSales(); newWeekSales.init(12); newWeekSales.getAverageSomeMonth(12); newWeekSales.getAverageSomeMonth(12,4); </script> </html>
运行结果如下(随机的):