Question

我试图在循环中按名称删除变量时遇到困难，发现用Magrittr管道执行此操作是不可能的（？）：

eg.names <- unlist(lapply(0:4, function(x){
  eg <- paste0('example.var.',as.character(x))
}))

for (examplename in eg.names) {
  assign(examplename, 10)
}

library('magrittr')

for (examplename in eg.names) {
  examplename %>%
    rm(list = as.character(.))
  print(exists(examplename))
}

### Gives:

# [1] TRUE
# [1] TRUE
# [1] TRUE
# [1] TRUE
# [1] TRUE
# Warning messages:
#   1: In rm(list = .) : object 'example.var.0' not found
# 2: In rm(list = .) : object 'example.var.1' not found
# 3: In rm(list = .) : object 'example.var.2' not found
# 4: In rm(list = .) : object 'example.var.3' not found
# 5: In rm(list = .) : object 'example.var.4' not found

### Piping `examplename` to `rm(list = as.character(.))` also doesn't work...

### Working non-%>% version:

for (examplename in eg.names) {
  rm(list = as.character(examplename))
}

在这里我是否应该避免在Magrittr中做些什么，或者实际上是否有某种方法呢？

Answer 1

这很好用：

for (examplename in eg.names) {
  examplename %>%
    rm(list = .,envir=globalenv())
  print(exists(examplename))
}
# [1] FALSE
# [1] FALSE
# [1] FALSE
# [1] FALSE
# [1] FALSE

使用magrittr将变量名称管道化为rm

1 个答案: