How do convert a categorical variable into multiple dummy variables in R?

Question

Here I have a dataset with a column name as Age = (24 or under, 25 to 34, 35 to 44, 45 to 54, 25 to 34, 24 or under,35 to 44, 25 to 34, 45 to 54)

Now I need to convert the values for the categorical variable "Age" as follows: 24 or under equal to 1, 25 to 34 equal to 2, 35 to 44 equal to 3, 45 to 54 equal to 4

Can anyone help me here?

Many thanks in advance.

Answer 1

You can use nested ifelse statements:

set.seed(12)
df <- data.frame(Age = c(sample(c("24 or under", "25 to 34", "35 to 44", "45 to 54"), 20, replace = T)))
df$Age_new <- ifelse(df$Age == "24 or under", 1,
                     ifelse(df$Age == "25 to 34", 2,
                            ifelse(df$Age == "35 to 44", 3, 4)))

Result:

df
           Age Age_new
1     25 to 34       2
2     35 to 44       3
3  24 or under       1
4     45 to 54       4
5  24 or under       1
6     35 to 44       3
7     45 to 54       4
8     25 to 34       2
9     45 to 54       4
10    35 to 44       3
11 24 or under       1
12    35 to 44       3
13    25 to 34       2
14 24 or under       1
15    25 to 34       2
16    35 to 44       3
17    25 to 34       2
18    25 to 34       2
19    35 to 44       3
20    25 to 34       2