assign函式在迴圈時候，給變數賦值，算是比較方便

1、給變數賦值

for (i in 1:(length(rowSeq)-1)){
  assign(paste("nginx_server_fields7_", i, sep = ""), nginx_server_fields7[(rowSeq[(i-1)+1]):(rowSeq[i+1]), ])
}

2、通過for迴圈給變數a1、a2、a3賦值

for (i in 1:3){
    assign(paste("a", i, sep = ""), i:10)
}

ls()
[1] "a1" "a2" "a3" "i"

> a1
 [1]  1  2  3  4  5  6  7  8  9 10
> a2
[1]  2  3  4  5  6  7  8  9 10
 

3、get和assign聯合用法

rm(list = ls())  #這個命令千萬慎重使用
for(i in 1:3){
     assign(paste("p", i, sep=""), i)
     tmp <- get(paste("p", i, sep=""))
     print(tmp)
 }
[1] 1
[1] 2
[1] 3
 ls()
[1] "i"   "p1"  "p2"  "p3"  "tmp"