Off topic:R merge columns in the same file with identical column names and remove duplicates

Question

[Seigfried]

Dear all

I have a dataframe containing columns with identical names for some reason. I wish to combine these columns with the same name with removing the duplicates

I tried using merge but I do not want to enter the column names one by one like merge (x, y)

horse   sheep   horse
A          A    A
B               B
C

This should give

horse   sheep
A          A
B
C

Is there any way to do this? I googled and found ways to do it 1 by 1 but I have a lot of columns