Does column exist and how to rearrange columns in R data frame -

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How do I add a column in the middle of the R data frame? I want to see that I have a column called "LastName" and then it does not already exist, then add it as the third column.

1) Test for survival: Use% in colnames in%, e.g.

& gt; Example (data.frame) # to get 'd' & gt; "Fac"% (d) [1] in% Colnames true & gt; % Colnames in "bar"% (d) [1] FALSE

2) You must essentially create a new data frame from the new half of the old data, your new column, and Second half: 

  & gt; Bar and lt; - Data. Frame (D [1: 3,1: 2], LastName = C ("Flim", "Flom", "Flame"), FAP = D [1: 3,3]) gt; Bar XY Last Name FAC 1 1 1 Flim C2 1 2 Flom A3 1 3 Flame A & gt;

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