Convert factor to date class for multiple columns

Question

I have 7 columns in my dataset. I want to convert 4 variables (2 to 5 column) from factor to date format. I can do it one column at a time, but I want to know if there is a

Answer 1

Given the format of your dates, you may try this:

# sample data
df <- data.frame(a = 1:2,
                 d1 = factor(c("2013/01/01", "2014/01/01")),
                 d2 = factor(c("2013/01/01", "2014/01/01")),
                 b = 3:4)

df[ , 2:3] <- lapply(df[ , 2:3], as.Date)

str(df)
# 'data.frame':  2 obs. of  4 variables:
# $ a : int  1 2
# $ d1: Date, format: "2013-01-01" "2014-01-01"
# $ d2: Date, format: "2013-01-01" "2014-01-01"
# $ b : int  3 4