Matching of patterns in a String in R Programming - agrep() Function

Find position of a Matched Pattern in a String in R Programming – grep() Function

Last Updated : 12 Apr, 2021

grep() function in R Language is used to search for matches of a pattern within each element of the given string.

Syntax:
grep(pattern, x, ignore.case=TRUE/FALSE, value=TRUE/FALSE)
Parameters:
pattern: Specified pattern which is going to be matched with given elements of the string.
x: Specified string vector.
ignore.case: If its value is TRUE, it ignores case.
value: If its value is TRUE, it return the matching elements vector, else return the indices vector.

Example 1:

Python3

# R program to illustrate
# grep function

# Creating string vector
x <- c("GFG", "gfg", "Geeks", "GEEKS")

# Calling grep() function
grep("gfg", x)
grep("Geeks", x)
grep("gfg", x, ignore.case = FALSE)
grep("Geeks", x, ignore.case = TRUE)

Output :

[1] 2
[1] 3
[1] 2
[1] 3 4

Example 2:

Python3

# R program to illustrate
# grep function

# Creating string vector
x <- c("GFG", "gfg", "Geeks", "GEEKS")

# Calling grep() function
grep("gfg", x, ignore.case = TRUE, value = TRUE)
grep("G", x, ignore.case = TRUE, value = TRUE)
grep("Geeks", x, ignore.case = FALSE, value = FALSE)
grep("GEEKS", x, ignore.case = FALSE, value = FALSE)

Output:

[1] "GFG" "gfg"
[1] "GFG"   "gfg"   "Geeks" "GEEKS"
[1] 3
[1] 4

Matching of patterns in a String in R Programming - agrep() Function

N

nidhi_biet

Improve

Article Tags :

Similar Reads

Matching of patterns in a String in R Programming - agrep() Function

agrep() function in R Language is used to search for approximate matches to pattern within each element of the given string.Â Syntax:Â agrep(pattern, x, ignore.case=FALSE, value=FALSE)Parameters:pattern: Specified pattern which is going to be matched with given elements of the string.Â x: Specified st

Seek a Match for the Pattern in the String in R Programming - pmatch() Function

pmatch() function in R Language is used to seek match for the pattern passed as argument. It returns the strings that begin with the pattern being searched. Syntax: pmatch(pat, string, nomatch) Parameters: pat: pattern vector to be searched string: vector to be matched nomatch: return when no match

Replace all the matches of a Pattern from a String in R Programming - gsub() Function

gsub() function in R Language is used to replace all the matches of a pattern from a string. If the pattern is not found the string will be returned as it is. Syntax: gsub(pattern, replacement, string, ignore.case=TRUE/FALSE) Parameters: pattern: string to be matched replacement: string for replacem

Find String Matches in a Vector or Matrix in R Programming - str_detect() Function

str_detect() Function in R Language is used to check if the specified match of the substring exists in the original string. It will return TRUE for a match found otherwise FALSE against each of the element of the Vector or matrix. Note: This function uses 'stringr' Library. Syntax: str_detect(string

Replace the First Match of a Pattern from a String in R Programming â€“ sub() Function

sub function in R Language is used to replace the first match of a pattern in a string. If there is a vector of string elements, then it will replace the first match of the pattern from all elements. Syntax: sub(pattern, replacement, string, ignore.case=TRUE/FALSE) Parameters: pattern: string to be

Check for a Pattern in the Vector in R Programming - grepl() Function

grepl() function in R Language is used to return the value True if the specified pattern is found in the vector and false if it is not found. Syntax: grepl(pattern, string, ignore.case=FALSE) Parameters: pattern: regular expressions pattern string: character vector to be searched ignore.case: whethe

Get the Last parts of a Data Set in R Programming - tail() Function

tail() function in R Language is used to get the last parts of a vector, matrix, table, data frame or function. Syntax: tail(x, n) Parameters: x: specified data types n: number of row need to be printed Example 1: Python3 # R program to illustrate # tail function # Calling the tail() function to # g

Get the First parts of a Data Set in R Programming - head() Function

head() function in R Language is used to get the first parts of a vector, matrix, table, data frame or function. Syntax: head(x, n) Parameters: x: specified data types n: number of row need to be printed Example 1: Python3 # R program to illustrate # head function # Calling the head() function to #

Getting Match of an Element within a Vector in R Programming - charmatch() Function

charmatch() function in R Programming Language is used to find matches between two arguments. Syntax: charmatch(x, table, nomatch = NA_integer_) Parameters:Â x: the values to be matchedtable: the values to be matched againstnomatch: the integer value to be returned at non-matching positionr - charma

Get a List of all the Attached Packages in R Programming - search() Function

search() function in R Language is used to get the list of all the attached packages in the R search path. Syntax: search() Parameters: This function takes no parameters. Example 1: Python3 1== # R program to list the packages # attached to R search path # Calling search() function search() Output: