您可以像使用$一样使用括号中的内容来访问列.

You can just use paste in brackets to access the column as you would otherwise do with $.

big.data[paste0(age.years[1])]

此外，您可以仅使用数字来访问像这样的列.

Additionally, you can use just the numbers to access the columns like this.

years <- c(1990:1992)
big.data[paste0("age.",years[1])]

然后循环将像这样工作.

And the loop will work like this.

for (iy in 1:length(years)){
  big.data$Y.60 <- NA
  big.data$Y.60  <- ifelse(big.data[paste0("age.",years[iy])] == 60,     +
     paste0("Y.",years[iy]),big.data$Y.60 ) 
 }

如果我正确理解了您的目的.

If I understood your purpose correctly.

更新:

或者是作者@jtd的替代答案，使用方括号代替粘贴.

Or an alternative answer from the author @jtd with brackets instead of paste.

for (iy in 1:length(age.years)) {
   big.data$Y = ifelse(big.data[[age.years[iy]]] == 60,
              big.data[[Y.years[iy]]],
              big.data$Y
              )
}