R 如何向所有列添加报价？

我正在尝试自动向数据帧中的所有元素添加引号，而不必显式地提供col名称。有什么办法可以做到吗

我试过：

x<-iris

for (i in colnames(x)){
  paste0('x$',i)<-paste0('"x$',i,'"')
}

---

x使用内置数据框
BOD
我们有以下内容。请注意，它不会覆盖输入，而是生成新的输出

replace(BOD, TRUE, lapply(BOD, shQuote, type = "cmd"))

给予：

  Time demand
1  "1"  "8.3"
2  "2" "10.3"
3  "3"   "19"
4  "4"   "16"
5  "5" "15.6"
6  "7" "19.8"

这里有一个解决方案：

x <- iris

x[] <- lapply(x, sprintf, fmt = '"%s"')


  Sepal.Length Sepal.Width Petal.Length Petal.Width  Species
1        "5.1"       "3.5"        "1.4"       "0.2" "setosa"
2        "4.9"         "3"        "1.4"       "0.2" "setosa"
3        "4.7"       "3.2"        "1.3"       "0.2" "setosa"
4        "4.6"       "3.1"        "1.5"       "0.2" "setosa"
5          "5"       "3.6"        "1.4"       "0.2" "setosa"
6        "5.4"       "3.9"        "1.7"       "0.4" "setosa"
...

x
x <- iris

x[] <- lapply(x, sprintf, fmt = '"%s"')


  Sepal.Length Sepal.Width Petal.Length Petal.Width  Species
1        "5.1"       "3.5"        "1.4"       "0.2" "setosa"
2        "4.9"         "3"        "1.4"       "0.2" "setosa"
3        "4.7"       "3.2"        "1.3"       "0.2" "setosa"
4        "4.6"       "3.1"        "1.5"       "0.2" "setosa"
5          "5"       "3.6"        "1.4"       "0.2" "setosa"
6        "5.4"       "3.9"        "1.7"       "0.4" "setosa"
...