Remove Multiple Columns from data.table in R
In this article, we are going to see how to remove multiple columns from data.table in the R Programming language.
Create data.table for demonstration:
R
# load the data.table package library ( "data.table" ) # create a data.table with 4 columns # they are id,name,age and address data = data.table (id = c (1,2,3) , name = c ( "sravan" , "bobby" , "satwik" ), age = c (23,21,17), address = c ( "kakumanu" , "ponnur" , "hyd" )) # display data |
Output:
Here we are going to remove multiple columns by using the index operator []
Syntax: data[ ,’:='(column1 = NULL, column2 = NULL, column n=NULL)]
where
- data is the input data.table
- column is the columns to be removed
- := is the operator to be loaded in the data.table
Example 1: R program to remove multiple columns from data.table
R
# load the data.table package library ( "data.table" ) # create a data.table with 4 columns # they are id,name,age and address data = data.table (id = c (1,2,3), name = c ( "sravan" , "bobby" , "satwik" ), age = c (23,21,17), address = c ( "kakumanu" , "ponnur" , "hyd" )) # remove age , name and address columns data[ , ':=' (age = NULL , address = NULL , name= NULL )] # display data |
Output:
Example 2: Remove only one column from data.table
R
# load the data.table package library ( "data.table" ) # create a data.table with 4 columns # they are id,name,age and address data = data.table (id = c (1,2,3), name = c ( "sravan" , "bobby" , "satwik" ), age = c (23,21,17), address = c ( "kakumanu" , "ponnur" , "hyd" )) # remove id column data[ , ':=' (id= NULL )] # display data |
Output:
Example 3: R program to remove all columns
R
# load the data.table package library ( "data.table" ) # create a data.table with 4 columns # they are id,name,age and address data = data.table (id = c (1,2,3), name = c ( "sravan" , "bobby" , "satwik" ), age = c (23,21,17), address = c ( "kakumanu" , "ponnur" , "hyd" )) # remove all columns data[ , ':=' (id= NULL ,age = NULL , address = NULL , name= NULL )] # display data |
Output:
Null data.table (0 rows and 0 cols)