col_order <- c("Species", "Petal.Width", "Sepal.Length",
"Sepal.Width", "Petal.Length")
my_data2 <- my_data[, col_order]
# Reorder by column name
df <- df[c("A", "B", "C")]
# Reorder by column index
df <- df[c(1, 3, 2)]
col_order <- c("Species", "Petal.Width", "Sepal.Length",
"Sepal.Width", "Petal.Length")
my_data2 <- my_data[, col_order]
my_data2
# or
my_data2 <- my_data[, c(5, 4, 1, 2, 3)]