How to add new column to an dataframe to the front not end

Question

How to add a new variable to an existing data frame  but I want to add to the front not end  eg  my dataframe is  b c d 1 2 3 1 2 3 1 2 3   I want to add a new variable a  so the dataframe will looks like  a b c d 0 1 2 3 0 1 2 3 0 1 2 3

User · Answer

The previous answers show 3 approaches

By creating a new data frame
By using "cbind"
By adding column "a", and sort data frame by columns using column names or indexes

Let me show #4 approach "By using "cbind" and "rename" that works for my case

1. Create data frame

df <- data.frame(b = c(1, 1, 1), c = c(2, 2, 2), d = c(3, 3, 3))

2. Get values for "new" column

new_column = c(0, 0, 0)

3. Combine "new" column with existed

df <- cbind(new_column, df)

4. Rename "new" column name

colnames(df)[1] <- "a"

User · Answer

cbind inherents order by its argument order   User your first column s  as your first argument  cbind fst col   df     fst col   df col1   df col2 1 0             0 2      -0 1 2 0             0 2      -0 1 3 0             0 2      -0 1 4 0             0 2      -0 1 5 0             0 2      -0 1   cbind df  last col     df col1   df col2  last col 1 0 2      -0 1             0 2 0 2      -0 1             0 3 0 2      -0 1             0 4 0 2      -0 1             0 5 0 2      -0 1             0

User · Answer

df  lt - data frame b   c 1  1  1   c   c 2  2  2   d   c 3  3  3   df      b c d    1 1 2 3    2 1 2 3    3 1 2 3  df  lt - data frame a   c 0  0  0   df  df      a b c d    1 0 1 2 3    2 0 1 2 3    3 0 1 2 3

User · Answer

Add column  a     gt  df  a    lt - 0  gt  df   b c d a 1 1 2 3 0 2 1 2 3 0 3 1 2 3 0      Sort by column using colum name    gt  df  lt - df c  a    b    c    d     gt  df   a b c d 1 0 1 2 3 2 0 1 2 3 3 0 1 2 3      Or sort by column using index    gt  df  lt - df colnames df  c 4 1 3     gt  df   a b c d 1 0 1 2 3 2 0 1 2 3 3 0 1 2 3

User · Answer

Use cbind e g   df  lt - data frame b   runif 6   c   rnorm 6   cbind a   0  df    giving    gt  cbind a   0  df    a         b          c 1 0 0 5437436 -0 1374967 2 0 0 5634469 -1 0777253 3 0 0 9018029 -0 8749269 4 0 0 1649184 -0 4720979 5 0 0 6992595  0 6219001 6 0 0 6907937 -1 7416569

User · Answer

If you want to do it in a tidyverse manner  try add column from tibble  which allows you to specifiy where to place the new column with  before or  after parameter   library tibble   df  lt - data frame b   c 1  1  1   c   c 2  2  2   d   c 3  3  3   add column df  a   0   before   1       a b c d   1 0 1 2 3   2 0 1 2 3   3 0 1 2 3

[r] How to add new column to an dataframe (to the front not end)?

1. Create data frame

2. Get values for "new" column

3. Combine "new" column with existed

4. Rename "new" column name

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