How to change column names in R?

Programming Language
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#1

A data frame is a tabular structure with fixed dimensions, of each rows as well as columns. Each element belonging to the data frame is indexed by a unique combination of the row and column number respectively. Column names are addressed by unique names.

colnames() method: colnames() method in R is used to rename and replace the column names of the data frame in R.
Syntax:
colnames(df) <- c(new_col1_name,new_col2_name,new_col3_name)

Example:

# declaring the columns of data frame
df = data.frame(
col1 = c('A', 'B', 'C', 'J', 'E', NA,'M'),
col2 = c(12.5, 9, 16.5, NA, 9, 20, 14.5),
col3 = c(NA, 3, 2, NA, 1, NA, 0))
  
# printing original data frame
print("Original data frame : ")
print(df)
  
print("Renaming columns names ")
  
# assigning new names to the columns of the data frame
colnames(df) <- c('C1','C2','C3')
  
# printing new data frame
print("New data frame : ")
print(df)

Output:


[1] “Original data frame : “
   col1 col2 col3
1    A 12.5   NA
2    B  9.0    3
3    C 16.5    2
4    J   NA   NA
5    E  9.0    1
6 <NA> 20.0   NA
7    M 14.5    0

[1] “Renaming columns names “
[1] “New data frame : “

    C1   C2 C3
1    A 12.5 NA
2    B  9.0  3
3    C 16.5  2
4    J   NA NA
5    E  9.0  1
6 <NA> 20.0 NA
7    M 14.5  0

setNames() method: setNames() method in R can also be used to assign new names to the columns contained within a list, vector or tuple.
Syntax:
setnames(df, c(names of new columns))

Example:

# declaring the columns of data frame
df = data.frame(
col1 = c('A', 'B', 'C', NA,'M'),
col2 = c(12.5, 9, 16.5,  20, 14.5),
col3 = c(NA, 3, 2, NA, 0))
  
# printing original data frame
print("Original data frame : ")
print(df)
  
# print("Renaming columns names ")
# renaming all the column names of data frame
df <- setNames(df, c("changed_Col1","changed_Col2","changed_Col3"))
  
print("Renamed data frame : ")
print(df)

Output:

[1] “Original data frame : “

    col1 col2 col3

1    A 12.5   NA
2    B  9.0    3
3    C 16.5    2
4 <NA> 20.0   NA
5    M 14.5    0
[1] “Renamed data frame : “

  changed_Col1 changed_Col2 changed_Col3

1            A         12.5           NA
2            B          9.0            3
3            C         16.5            2
4         <NA>         20.0           NA
5            M         14.5            0