我正在学习Java。当我打电话时go(x)，我得到 \xe2\x80\x98int\xe2\x80\x99。为什么不是 \xe2\x80\x98Short\xe2\x80\x99？
public class test {\n public static void go(Short n) {System.out.println("Short");}\n public static void go(int n) {System.out.println("int");}\n \n public static void main(String[] args) {\n short x=11;\n go(x);\n }\n}\n我有两个要与每一行进行比较并添加新列的data.tables。
DT1 <- data.table(ID=c("F","A","E","B","C","D","C"),
num=c(59,3,108,11,22,54,241),
value=c(90,47,189,72,42,86,280))
DT2 <- data.table(Mark=c("Mary","Abner","Bonnie","Trista","Norman"),
numA=c(48,20,88,237,10),
numB=c(60,326,54,268,89),
valueA=c(78,34,78,270,60),
valueB=c(92,190,90,385,75))
我的目标：
我想在DT1中找到num和value，并且在DT2中有numA和numB范围。
例如：
对于F行中DT1中的num = 59和value = 90的行，还必须匹配：
num（59）> DT2 $ numA（48）＆num（59）<DT2 $ numB（60）＆值（90）> DT2 $ valueA（78）＆值（90）<DT2 $ valueB（92）
比赛！因此添加新的列名称结果，其值为dt2标记
如果没有匹配项，请将其设置为Undefined
所需结果：
DT3 <- data.table(ID=c("F","A","E","B","C","D","C"),
num=c(59,3,108,11,22,54,241),
value=c(90,47,189,38,42,86,280),
result=c("Mary","Undefined","Abner","Norman",
"Abner","Abner","Trista"))
如何确保每一行都有比较并添加新列？
我有一个data.table，我想使用Time列来合并数据以减少数据。
library(data.table)
DT <- data.table(ID=c("A","A","A","B","B","C","C","C","C","D"),
Time=c("2019-01-16 15:52:03","2019-01-16 16:01:04","2019-01-26 01:22:54",
"2019-02-18 17:00:08","2019-02-18 17:05:44",
"2019-03-16 13:23:42","2019-03-16 15:52:03","2019-06-04 12:01:04","2019-06-04 16:20:54",
"2019-03-16 13:23:42"),
place=c("Vienna","France","Berlin","Rome","Washington",
"Bangkok","Ottawa","Tokyo","SouthKorea","Singapore"))
如果在当天，同一天、相同的Id会被合并。
不同的日子，无需合并
输出：
ID Time place
1 A 2019-01-16 Vienna-France
2 A 2019-01-26 Berlin
3 B 2019-02-18 Rome-Washington
4 C 2019-03-16 Bangkok-Ottawa
5 C 2019-06-04 Tokyo-SouthKorea
6 D 2019-03-16 Singapore
我应该怎么办？谢谢。