Matching of patterns in a String in R Programming - agrep() Function Last Updated : 14 Apr, 2021 Summarize Comments Improve Suggest changes Share Like Article Like Report agrep() function in R Language is used to search for approximate matches to pattern within each element of the given string. Syntax: agrep(pattern, x, ignore.case=FALSE, value=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 ignore 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 # agrep function # Creating string vector x <- c("GFG", "gfg", "Geeks", "GEEKS") # Calling agrep() function agrep("gfg", x) agrep("Geeks", x) agrep("gfg", x, ignore.case = TRUE) agrep("Geeks", x, ignore.case = TRUE) Output : [1] 2 [1] 3 [1] 1 2 [1] 3 4 Example 2: Python3 # R program to illustrate # agrep function # Creating string vector x <- c("GFG", "gfg", "Geeks", "GEEKS") # Calling agrep() function agrep("gfg", x, ignore.case = TRUE, value = TRUE) agrep("G", x, ignore.case = TRUE, value = TRUE) agrep("Geeks", x, ignore.case = FALSE, value = FALSE) agrep("GEEKS", x, ignore.case = FALSE, value = FALSE) Output: [1] "GFG" "gfg" [1] "GFG" "gfg" "Geeks" "GEEKS" [1] 3 [1] 4 Comment More infoAdvertise with us Next Article Replace all the matches of a Pattern from a String in R Programming - gsub() Function K Kanchan_Ray Follow Improve Article Tags : R Language R-strings R String-Functions Similar Reads Find position of a Matched Pattern in a String in R Programming – grep() Function 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 str 1 min read 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 1 min read 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 1 min read Replace the First Match of a Pattern from a String in R Programming – 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 1 min read 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 2 min read 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 1 min read Like