how to remove columns using column names in r code example

Example 1: r data frame remove column

df$columnName <- NULL

Example 2: how to delete columns in df in r

> df <- data.frame(x=1:5, y=6:10, z=11:15, a=16:20)
> df <- subset (df, select = -c(x:z))
> df
a
1 16
2 17
3 18
4 19
5 20