Question 3

Load Data

raw.data <-"555-1239Moe Szyslak(636) 555-0113Burns, C. Montgomery555-6542Rev. Timothy Lovejoy555 8904Ned Flanders636-555-3226Simpson, Homer5553642Dr. Julius Hibbert"   
library(stringr)
name <- unlist(str_extract_all(raw.data, "[[:alpha:]., ]{2,}"))

Split Name

Namesplit <- str_extract_all(name, "\\w+(\\,)?(\\.\\s\\w+)?" )

Determine whether it’s first name by comma and if so, sweet 1st and 2nd spot. Then combine.

i=1
NameFirst_Last <- list()
for (i in 1:length(Namesplit)){
FirstName_False <- str_count(Namesplit[[i]][1],"\\,")
if (FirstName_False > 0) {
temp <- Namesplit[[i]][1]
Namesplit[[i]][1] <- Namesplit[[i]][2]
Namesplit[[i]][2] <- temp
Namesplit[[i]][2] <- unlist(str_extract_all(Namesplit[[i]][2],"\\w+"))
}
NameFirst_Last[[i]] <- paste(Namesplit[[i]][1], Namesplit[[i]][2])
i = i+1
}

Title detection

string_title <- c("Rev.", "Dr.")
title_detect <- sapply(string_title, function(x) str_detect(NameFirst_Last,x))
title_detect_logical <- as.logical(title_detect[,1] + title_detect[,2])

Second name detection

period_detect <- str_detect(NameFirst_Last, "\\.")
second_name_detect <- as.logical(period_detect - title_detect_logical)

Question 4

Describe the types of strings that conform to the following regular expressions and construct an example that is matched by the regular expression.

Description for each in the code

str_detect("22394$","[0-9]+\\$")   #Many numbers and end with $
## [1] TRUE
str_detect("baxx", "\\b[a-z]{1,4}\\b")  #empty string at edge of a word followed by lower alphabet charaters from 1 to 4 times, then follwed by empty string at edge of a word
## [1] TRUE
str_detect("string.txt",".*?\\.txt$")  #any character many times as optional followed by .txt and end of string
## [1] TRUE
str_detect("01/31/2017","\\d{2}/\\d{2}/\\d{4}") #basic month/day/year format
## [1] TRUE
str_detect("<abcd>anything</abcd>","<(.+?)>.+?</\\1>") # < followed by parenthesis so that it can be backrefenced.  closed by >.  Followed by any number of character string,  opened by </ then repeat with what was in the parenthesis then close with >
## [1] TRUE