Replace Specific Characters in String in R

In this article, we will discuss how to replace specific characters in a string in R Programming Language.

Method 1: Using gsub() function

We can replace all occurrences of a particular character using gsub() function.

Syntax: gsub(character,new_character, string) 

Parameters:

• string is the input string
• character is the character present in the string to be replaced
• new_character is the new character to be placed in the place in the existing character

Example: R program to replace character in a string using gsub() function

# consider a string "Hello Geek"
# replace the character 'e' in  "Hello 
# Geek" with "E"
print(gsub("e", "E", "Hello Geek") )

# consider a string "Python and java"
# replace the character 'a' in  "Python 
# and java" with "M"
print(gsub("a", "M", "Python and java") )

Output:

[1] "HEllo GEEk"
[1] "Python Mnd jMvM"

Method 2: Using sub() function

We can replace only the first occurrence of a particular character using sub() function, it will replace only the first occurrence character in the string

Syntax: sub(character,new_character, string)

Parameters:

• string is the input string
• character is the character present in the string to be replaced
• new_character is the new character to be placed in the place in the existing character

Example: R program to replace character in a string using sub() function

# consider a string "Hello Geek"
# replace the character 'e' in  "Hello Geek" 
# with "E"
print(sub("e", "E", "Hello Geek") )

# consider a string "Python and java"
# replace the character 'a' in  "Python and java"
# with "M"
print(sub("a", "M", "Python and java") )

Output:

[1] "HEllo Geek"
[1] "Python Mnd java"

Method 3: Using str_replace_all() function

str_replace_all() is also a function that replaces the character with a particular character in a string. It will replace all occurrences of the character. It is available in stringr package. So, we need to install and load the package

install: install.packages("stringr")
load: library("stringr")  

Syntax: str_replace_all(string, "character", "new_character")

Parameters:

• string is the input string
• character is the character present in the string to be replaced
• new_character is the new character to be placed in the place in the existing character

Example: R program to replace character in a string using str_replace_all() function

# load the stringr package
library("stringr")

# consider a string "Hello Geek"
# replace the character 'e' in  "Hello Geek" 
# with "E"
print(str_replace_all( "Hello Geek","e", "E") )

# consider a string "Python and java"
# replace the character 'a' in  "Python and java"
# with "M"
print(str_replace_all("Python and java","a", "M") )

Output:

[1] "HEllo GEEk"
[1] "Python Mnd jMvM"

Method 4: Using str_replace() function

str_replace() is also a function that replaces the character with a particular character in a string. It will replace only the first occurrence.

Syntax: str_replace(string, "character", "new_character")

Parameters:

• string is the input string
• character is the character present in the string to be replaced
• new_character is the new character to be placed in the place in the existing character

Example: R program to replace character in a string using str_replace() function

# load the stringr package
library("stringr")

# consider a string "Hello Geek"
# replace the character 'e' in  "Hello Geek" 
# with "E"
print(str_replace( "Hello Geek","e", "E") )

# consider a string "Python and java"
# replace the character 'a' in  "Python and java"
# with "M"
print(str_replace("Python and java","a", "M") )

Output:

[1] "HEllo Geek"
[1] "Python Mnd java"