Assignment - 7
QUESTION - 1 : [abc]: matches a, b, or c.
grep(\"[abc]\", Carnames, value = TRUE, fixed = TRUE)
#Ans - character(0)
grep(\"[abc]\", Carnames, value = TRUE, fixed = FALSE)
ANSWER -
[1] \"Mazda RX4\" \"Mazda RX4 Wag\" \"Datsun 710\" \"Hornet Sportabout\" \"Valiant\" \"Merc 240D\"
[7] \"Merc 230\" \"Merc 280\" \"Merc 280C\" \"Merc 450SE\" \"Merc 450SL\" \"Merc 450SLC\"
[13] \"Cadillac Fleetwood\" \"Lincoln Continental\" \"Chrysler Imperial\" \"Fiat 128\" \"Honda Civic\" \"Toyota Corolla\"
[19] \"Toyota Corona\" \"Dodge Challenger\" \"AMC Javelin\" \"Camaro Z28\" \"Pontiac Firebird\" \"Fiat X1-9\"
[25] \"Porsche 914-2\" \"Lotus Europa\" \"Ford Pantera L\" \"Ferrari Dino\" \"Maserati Bora\"
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QUESTION - 2 : [a-z]: matches every character between a and z
ANSWER :
rownames_to_column(mtcars,var=\"carname\") -> mycars
Carnames <- mycars$carname
grep(\"[a-z]\", Carnames, value = TRUE, fixed = FALSE)
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QUESTION - 3 : [^abc]: matches anything except a, b, or c.
ANSWER :
grep(\"[abc]\", Carnames, value = TRUE, fixed = FALSE, invert = TRUE)
#Ans [1] \"Hornet 4 Drive\" \"Duster 360\" \"Volvo 142E\"
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QUESTION - 4 : [:punct:]: punctuation.
ANSWER :
# punctuation characters - ! \" # $ % & ’ ( ) * + , - . / : ; < = > ? @ [ ] ^ _ ` { | } ~.
strings <- c(\"a^b\", \"ab\", \"ab$c\", \"abd\", \"ab`e\", \"ab12\", \"cf&\",\"vh#\")
grep(\"[[:punct:]]\", strings, value = TRUE)
#Ans [1] \"a^b\" \"ab$c\" \"ab`e\" \"cf&\" \"vh#\"
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QUESTION -5 : letters.
ANSWER :
grep(\"[[:alpha:]]\", strings, value = TRUE)
#Ans [1] \"a^b\" \"ab\" \"ab$c\" \"abd\" \"ab`e\" \"ab12\" \"cf&\" \"vh#\"
grep(\"[:alpha:]\", strings, value = TRUE)
#Ans [1] \"a^b\" \"ab\" \"ab$c\" \"abd\" \"ab`e\" \"ab12\" \"vh#\"
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QUESTION - 6 : lower case letters
ANSWER :
string1 <- c(\"a^bC\", \"aBbcf\", \"Mcab$c\", \"abd\", \"abe\", \"abJ12\", \"cf&\",\"vh#\", \"NMF\")
grep(\"[[:lower:]]\",string1, value = TRUE)
#Ans [1] \"a^bC\" \"aBbcf\" \"Mcab$c\" \"abd\" \"abe\" \"abJ12\" \"cf&\" \"vh#\"
grep(\"[a-z]\",string1, value = TRUE)
#ans [1] \"a^bC\" \"aBbcf\" \"Mcab$c\" \"abd\" \"abe\" \"abJ12\" \"cf&\" \"vh#\"
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QUESTION - 7 : Upper case letters
ANSWER :
grep(\"[A-Z]\", string1, value = TRUE)
#Ans - [1] \"a^bC\" \"aBbcf\" \"Mcab$c\" \"abJ12\" \"NMF\"
grep(\"[[:upper:]]\", string1, value = TRUE)
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QUESTION - 8 : Digits
ANSWER :
nums <- c(\"a^1C\", \"a4bc6\", \"Mcab$c\", \"abd\", 324, \"abJ12\", \"cf&\",\"vh#\", \"N0F\")
grep(\"[[:digit:]]\",nums, value = TRUE)
#Ans [1] \"a^1C\" \"a4bc6\" \"324\" \"abJ12\" \"N0F\"
grep(\"[0-9]\", nums, value = TRUE)
#Ans [1] \"a^1C\" \"a4bc6\" \"324\" \"abJ12\" \"N0F\"
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QUESTION - 9 : Hex digits
ANSWER :
grep(\"[[:xdigit:]]\",nums, value = TRUE)
#ans [1] \"a^1C\" \"a4bc6\" \"Mcab$c\" \"abd\" \"324\" \"abJ12\" \"cf&\" \"N0F\"
grep(\"[0-9A-Fa-f]\", nums, value = TRUE)
#ans [1] \"a^1C\" \"a4bc6\" \"Mcab$c\" \"abd\" \"324\" \"abJ12\" \"cf&\" \"N0F\"
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QUESTION - 10 : Letters and numbers
ANSWER :
grep(\"[[:alnum:]]\",nums, value = TRUE)
#ans [1] \"a^1C\" \"a4bc6\" \"Mcab$c\" \"abd\" \"324\" \"abJ12\" \"cf&\" \"vh#\" \"N0F\"
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QUESTION - 11 : Control characters
ANSWER
numctrls <- c(\"a^1C\", \"a4 bc6\", \"Mca\\b$c\", \"a]d\", 324, \"abJ12\", \"cf&\",\"{h#\", \"N0F@\", \"bjcd\", \"c#*n\", \"{)}\")
grep(\"[:cntrl:]\", numctrls , value = TRUE) %>% str()
#Ans [1] \"a4 bc6\" \"Mca\\b$c\" \"cf&\" \"bjcd\" \"c#*n\"
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QUESTION - 12 : [:graph:]: letters, numbers, and punctuation.
ANSWER :
grep(\"[[:graph:]]\", numctrls, value = TRUE )
#Ans [1] \"a^1C\" \"a4 bc6\" \"Mca\\b$c\" \"a]d\" \"324\" \"abJ12\" \"cf&\" \"{h#\" \"N0F@\" \"bjcd\" \"c#*n\" \"{)}\"
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QUESTION - 13: [:print:]: letters, numbers, punctuation, and whitespace.
ANSWER :
grep(\"[[:print:]]\", numctrls, value = TRUE )
#Ans [1] \"a^1C\" \"a4 bc6\" \"Mca\\b$c\" \"a]d\" \"324\" \"abJ12\" \"cf&\" \"{h#\" \"N0F@\" \"bjcd\" \"c#*n\" \"{)}\"
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QUESTION - 14 : [:space:] : space
ANSWER :
grep(\"[[:space:]]\", numctrls, value = TRUE )
#ans [1] \"a4 bc6\"
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QUESTION - 15 : [:blank:] : spaces and tabs
ANSWER :
numctrls1 <- c(\"a^1C\", \"a4 bc6\", \"Mca\\b$c\", \"a]d\", 324, \"abJ12\", \"cf&\",\"{h#\", \"N0F@\", \"bjcd\", \"c#*n\", \"{)}\", \" \")
grep(\"[[:blank:]]\", numctrls1, value = TRUE )
#Ans [1] \"a4 bc6\" \" \"
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