Adding new column in R based on conditions in Data frame subset

Question

I have the following dataset:

 df <- data.frame("attribute"=c('name', 'age', 'location'),
                "A"=c(1,0,0), "B"=c(0,1,1), "C"=c(1,0,1))
 names(df) <- c("attribute", "A", "B", "C")
 df

    attribute   A B C
        name    1 0 1
        age     0 1 0
     location   0 1 1

• I want to add a new column in R that contains one of the column names among A, B C.
• The condition is that one of the attributes name, age, location should match with one of the columns A, B C.

• The first column name whose value of the attribute is one should be listed as an additional column as follows:

    attribute   A B C Column
        name    1 0 1  A
        age     0 1 0  B
     location   0 1 1  B
  

  for(i in df$attribute){for(j in c("A", "B", "C")}print(names(df) [names(df)%in%c("A", "B", "C")][i]==1)

I am unable to solve this.

Answer 1

We can use max.col

df$Column <- names(df)[-1][max.col(df[-1], 'first')]
df$Column
#[1] "A" "B" "B"