The gsub() method in base R is used to replace all the matches of a pattern from a string. In case the pattern is not contained within the string, it will be returned as it is. It takes regular expression as a parameter which is used to replace with a new specified string.
Syntax:
gsub(pattern, replacement, string)
Parameters :
- pattern: the string to be matched
- replacement: the string to be used for replacement
- string: string
Example:
In this example, the $ sign in the string variable is replaced with "" (blank character) using the gsub() method.
# declaring a string
str = "$Remove Dollar $Sign"
print("Original String")
print(str)
# removing dollar sign from string
str_mod = gsub("\\$", "", str)
print("Modified String")
print(str_mod)
Output
[1] "Original String" [1] "$Remove Dollar $Sign" [1] "Modified String" [1] "Remove Dollar Sign"
Dollar signs can also be removed from a dataframe column or row, by using the gsub() method. All the instances of the $ sign are removed from the entries contained within the data frame.
Example:
In this example, all the instances of $ sign is replaced with a blank character in col2 of the data frame.
# declaring a data frame
data_frame < - data.frame(col1=c(1: 5),
col2=c("Ge$eks$", "$For",
"Geeks", "$I$s", "$Fun$"))
print("Original DataFrame")
print(data_frame)
# removing $ sign from data frame column
data_frame$col2 = gsub("\\$", "", data_frame$col2)
print("Modified DataFrame")
print(data_frame)
Output
A string vector can also be specified containing different strings which may or may not contain $ sign within it. The gsub() method can also be used to remove occurrences of $ sign from the vector.
Example:
# declaring a data frame
str_vec < - c("Ge$eks$", "$For", "Geeks",
"$I$s", "$Fun$")
print("Original String")
print(str_vec)
# removing $ sign from data frame column
str_mod = gsub("\\$", "", str_vec)
print("Modified String")
print(str_mod)
Output
[1] "Original String" [1] "Ge$eks$" "$For" "Geeks" "$I$s" "$Fun$" [1] "Modified String" [1] "Geeks" "For" "Geeks" "Is" "Fun"