首先检查下两个for语句的逻辑有没有问题
另外，R是可以做辅助变量的
给你放一个例子——
# 给同学对象增加新的行为
> student.correcting <- function(x) print("帮助老师批改作业")
# 辅助变量用于设置初始值
> char0 = character(0)
# 实现继承关系
> create <- function(classes=char0, parents=char0) {
+ mro <- c(classes)
+ for (name in parents) {
+ mro <- c(mro, name)
+ ancestors <- attr(get(name),'type')
+ mro <- c(mro, ancestors[ancestors != name])
+ }
+ return(mro)
+ }
# 定义构造函数，创建对象
> NewInstance <- function(value=0, classes=char0, parents=char0) {
+ obj <- value
+ attr(obj,'type') <- create(classes, parents)
+ attr(obj,'class') <- c('homework','correcting','exam')
+ return(obj)
+ }
# 创建父对象实例
> StudentObj <- NewInstance()
# 创建子对象实例
> s1 <- NewInstance('普通同学',classes='normal', parents='StudentObj')
> s2 <- NewInstance('课代表',classes='leader', parents='StudentObj')
# 给课代表，增加批改作业的行为
> attr(s2,'class') <- c(attr(s2,'class'),'correcting')
# 查看普通同学的对象实例
> s1
[1] "普通同学"
attr(,"type")
[1] "normal" "StudentObj"
attr(,"class")
[1] "homework" "correcting" "exam"
# 查看课代表的对象实例
> s2
[1] "课代表"
attr(,"type")
[1] "leader" "StudentObj"
attr(,"class")
[1] "homework" "correcting" "exam" "correcting"
扫码加好友，拉您进群
全部版块
我的主页
收藏
