How to Replace NAs with Strings in R?

Last Updated : 28 Nov, 2021

In this article, we will discuss how to Replace NAs with strings in R Programming Language. NA stands for Not a Number, we can replace NA with strings in the dataframe.

Create Dataframe for demonestration:

R 
# create a dataframe
data = data.frame(name = c("sravan","ojaswi",NA,"ramesh"),
                  subjects = c(NA,"java","jsp",NA),
                  address = c(NA,"hyd","tenali","guntur"))

# display
data

Output:

    name subjects address
1 sravan     <NA>    <NA>
2 ojaswi     java     hyd
3   <NA>      jsp  tenali
4 ramesh     <NA>  guntur

Example 1: Replace NAs with Strings in One Column

we can replace NA's with strings in particular column using replace_na() function, we have to import tidyr package

Syntax: dataframe$column_name%>% replace_na('string')

where

  1. dataframe  is the input dataframe
  2. column_name is the column replace with the string

R program to replace NAs with string in the given column

R 
# load the library
library("tidyr")

# create a dataframe
data = data.frame(name = c("sravan","ojaswi",NA,"ramesh"),
                  subjects = c(NA,"java","jsp",NA),
                  address = c(NA,"hyd","tenali","guntur"))

# display
print(data)

# replace NA with python in subjects column
data$subjects = data$subjects %>% replace_na('python')

# replace NA with sri devi in name column
data$name = data$name %>% replace_na('sri devi')

print(data)

Output:

   name subjects address
1 sravan     <NA>    <NA>
2 ojaswi     java     hyd
3   <NA>      jsp  tenali
4 ramesh     <NA>  guntur


   name subjects address
1 sravan     <NA>    <NA>
2 ojaswi     java     hyd
3   <NA>      jsp  tenali
4 ramesh     <NA>  guntur

Example 2: Replace NAs with Strings in Multiple Columns

Here we are using the same method as above but, to replace in multiple columns we have to specify multiple columns in a list function

Syntax: dataframe %>% replace_na(list(column1 = 'string', column2 = 'string',.,columnn = 'string',))

R 
# load the library
library("tidyr")

# create a dataframe
data = data.frame(name = c("sravan","ojaswi",NA,"ramesh"),
                  subjects = c(NA,"java","jsp",NA),
                  address = c(NA,"hyd","tenali","guntur"))

# display
print(data)


# replace NA with python in subjects
# column and sri devi in name column
data = data %>% replace_na(list(subjects='python', name='sri devi'))

print(data)

Output:

   name subjects address
1 sravan     <NA>    <NA>
2 ojaswi     java     hyd
3   <NA>      jsp  tenali
4 ramesh     <NA>  guntur


   name subjects address
1 sravan     <NA>    <NA>
2 ojaswi     java     hyd
3   <NA>      jsp  tenali
4 ramesh     <NA>  guntur
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