Data() :year(2000),month(1),day(1){ } 这个是在类内的构造函数吗?属于无参还是有参函数?另外想问下,我看过在类中派生类中设了无参无定义函数,无参无定义函数像A（）{ }有什么用了?

DATA Data data data In 2007, the latest year for which comprehensive data were available,这句话怎么翻译啊? matlab data=fread(,[m,n],); data_block=data(,num1:num2,); 第二句冒号和num1、2含义 有关SAS的程序说明data work.profit;infile sales;input Year 1-4 Expenses 6-10 Revenue 12-16;run;proc means data=work.profit;run;proc print data=work.profit;run;proc sort data=work.profit;by year;run;这个程序每个语句的意思~ 英语翻译The papers are ordered by year of publication,which is the standard way of data presentation in the software. Requires a minimum data service starting at $15/month.2 year contract & new activation required要准确翻译 i'm in year 4 this yeari'm in year 4 this year如何解释, i'm in year 4 this year作何解释 if (year < 2000) year=year+1900为什么 year=year+1900 急问：firm-year observation是什么意思?firm-year是公司年度的意思吗? 原句说的是： Our examination is based on the data of 289,055 firm-year observations from 1991 to 2010. I'm g___ there next year. there are twelve (m ) in a year I'm the year of the data 中文翻译 Data submission