help( sum )
strings <- c(  "abcd",  "cdab",  "cabd",  "c abd" )
strings
args( grep )
grep(  pattern="dab", x=strings )  
grep(  "dab", strings, value=TRUE ) 
grepl( "dab", strings ) 
grep( "ab", strings, value=TRUE )
grep( "ab", strings, value=TRUE )
grep( "^ab", strings, value=TRUE )
grep( "ab$", strings, value=TRUE )
strings <- c("abcd", "cdab", "cabd", "c abd", "cd^ab" )
grep( "^", strings, value=TRUE )
grep( "", strings, value=TRUE )
grep( "\\^", strings, value=TRUE )
grep( "\\bab", strings, value=TRUE )
grep( "^ab", strings, value=TRUE )
grep( "\\Bab", strings, value=TRUE )
grep( "ab$", strings, value=TRUE )
grepl( "^ab", strings )
grepl( "\\bab", strings )
condition.01 <- grepl( "^ab", strings )
condition.02 <- grepl( "\\bab", strings )
condition.02 & ! condition.01
strings[ condition.02 & ! condition.01 ]
grep( "ab", strings, value=TRUE )
strings
grep( "AB", strings, value=TRUE )
args( grep )
grep( "AB", strings, value=TRUE, ignore.case=FALSE )
grep( "AB", strings, value=TRUE, ignore.case=TRUE )
grep( "AB", strings, value=TRUE )
grep( "[ab]|[AB]", strings, value=TRUE )
grep( "[aA][bB]", strings, value=TRUE )
toupper( strings )
args( gsub )
c("finland", "iceland", "michael landon")
gsub( "land", "LAND", c("finland", "iceland", "michael landon") )
gsub( "land$", "LAND", c("finland", "iceland", "michael landon") )
strings <- c("ht","hot","hoot","hooot")
grep("h*t", strings, value = TRUE)
grep("h.t", strings, value = TRUE)
strings <- c("ht","hot","hoot","hooot", "hat")
grep("h.t", strings, value = TRUE)
grep("ho+t", strings, value = TRUE)
grep("ho?t", strings, value = TRUE)
grep("ho{1,2}t", strings, value = TRUE)
grep("ho{2,}t", strings, value = TRUE)
grep("ho{2}t", strings, value = TRUE)
strings <- c("ded", "dead","dad","deed", "deaad", "deeed" )
grep( "^de|ad$", strings, value=TRUE )
grep( "^d[ea]d$", strings, value=TRUE )
grep( "^d[ea]?d$", strings, value=TRUE )
strings <- c("ded", "dead","dad","deed", "deaad", "deeed","dd" )
grep( "^d[ea]?d$", strings, value=TRUE )
grep( "^d[ea]+d$", strings, value=TRUE )
grep( "^d[ea]{1,2}d$", strings, value=TRUE )
grep( "^d[a-zA-Z]{1,2}d$", strings, value=TRUE )
help( grep )
grep( "^d⁠[[:alnum:]]⁠{1,2}d$", strings, value=TRUE )
grep( "^d[:alpha:]{1,2}d$", strings, value=TRUE )
grep( "^d[[:alpha:]]{1,2}d$", strings, value=TRUE )
grep( "^d[ea]{1,2}d$", strings, value=TRUE )
grep( "^d[ea]{2}d$", strings, value=TRUE )
grep( "^d[ea]{2,}d$", strings, value=TRUE )
grep( "^d['ea']{2,}d$", strings, value=TRUE )
grep( "^d['ea]{2,}d$", strings, value=TRUE )
grep( "^dead$", strings, value=TRUE )
grep( "^d[e][a]d$", strings, value=TRUE )
strings <- c("ded", "dead","dad","deed", "deaad", "deeed","deeaad" )
strings <- c("ded", "dead","dad","deed", "deaad", "deeed","deeaad","daad" )
strings
grep( "^d[e][a]d$", strings, value=TRUE )
grep( "^d[e]?[a]d$", strings, value=TRUE )
grep( "^d[e]*[a]d$", strings, value=TRUE )
strings
grep( "^d[e]+[a]d$", strings, value=TRUE )
grep( "^d[e]{1,}[a]d$", strings, value=TRUE )
"deeaad"
"deaad"
strings <- c("ded", "dead","dad","deed", "deaad", "deeed","deeaad","daad","deeead" )
grep( "^d[e]{1,}[a]d$", strings, value=TRUE )
grep( "^d[e]{1,}[a]{1,}d$", strings, value=TRUE )
strings
grep( "^d[e]{0,}[a]{1,}d$", strings, value=TRUE )
grep( "^d[e]{1,}[a]{0,}d$", strings, value=TRUE )
grep( "^d[e]{0,}[a]{0,}d$", strings, value=TRUE )
grep( "^d[e]{1,}[a]d$", strings, value=TRUE )
"deeaad"
grep( "^d[e]{1,}.d$", strings, value=TRUE )
getwd()
usethis::create_package( "montyhall" )
help( sum )