Assignment_3_Adriana

#Load packages and import majors list from Github

library(usethis)
library(tidyverse)

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## ✔ lubridate 1.9.3     ✔ tidyr     1.3.1
## ✔ purrr     1.0.2     
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library(readr)

url <- "https://raw.githubusercontent.com/fivethirtyeight/data/master/college-majors/majors-list.csv"

majors_list <- read.csv(url)

##1. Using the 173 majors listed in fivethirtyeight.com’s College Majors dataset [https://fivethirtyeight.com/features/the-economic-guide-to-picking-a-college-major/], provide code that identifies the majors that contain either “DATA” or “STATISTICS”

filtered_majors <- subset(majors_list, grepl("DATA|STATISTICS", Major))

#2 Write code that transforms the data below: [1] “bell pepper” “bilberry” “blackberry” “blood orange” [5] “blueberry” “cantaloupe” “chili pepper” “cloudberry”
[9] “elderberry” “lime” “lychee” “mulberry”
[13] “olive” “salal berry”

into

c(“bell pepper”, “bilberry”, “blackberry”, “blood orange”, “blueberry”, “cantaloupe”, “chili pepper”, “cloudberry”, “elderberry”, “lime”, “lychee”, “mulberry”, “olive”, “salal berry”)

vector <- c("bell pepper", "billberry", "blackberry", "blood orange", "blueberry", "cantaloupe", "chili pepper", "cloudberry", "elderberry", "lime", "lychee", "mulberry", "olive", "salal berry")
print(vector)

##  [1] "bell pepper"  "billberry"    "blackberry"   "blood orange" "blueberry"   
##  [6] "cantaloupe"   "chili pepper" "cloudberry"   "elderberry"   "lime"        
## [11] "lychee"       "mulberry"     "olive"        "salal berry"

Return :c(“bell pepper”, “bilberry”, “blackberry”, “blood orange”, “blueberry”, “cantaloupe”, “chili pepper”, “cloudberry”, “elderberry”, “lime”, “lychee”, “mulberry”, “olive”, “salal berry”)

string_with_quotes <- paste0('"', paste(vector, collapse = '","'), '"')
print(string_with_quotes)

## [1] "\"bell pepper\",\"billberry\",\"blackberry\",\"blood orange\",\"blueberry\",\"cantaloupe\",\"chili pepper\",\"cloudberry\",\"elderberry\",\"lime\",\"lychee\",\"mulberry\",\"olive\",\"salal berry\""

dput(vector)

## c("bell pepper", "billberry", "blackberry", "blood orange", "blueberry", 
## "cantaloupe", "chili pepper", "cloudberry", "elderberry", "lime", 
## "lychee", "mulberry", "olive", "salal berry")

#3 REGEX Describe, in words, what these expressions will match: (.)\1\1

1. This will match any string that contains three identical characters in a row.

“(.)(.)\2\1”

2. This will match any string that consists of a quotation mark followed by two characters and the literal string \2\1, and a closing quotation mark. The literal string includes \2\1 because there is an escape backslash present.

(..)\1

3. I think this will match a string where the first two characters are the same followed by another 2 adjacent repeat characters. The backslash is referring to group 1.

“(.).\1.\1”

4. This will match any string that consists of a quotation mark followed by any two characters, followed by the literal string \1 and any character, then another literal \1 and ends with a closing quotation mark.

“(.)(.)(.).*\3\2\1”

5. This will match any string starting with a quotation mark and consisting of 3(any) or more characters and then the literal string \3\2\1 followed by a closing quotation mark.

#4 Construct regular expressions to match words that:

1. Start and end with the same character.: ^(.).*\1$

• ^ and $: Asserts the start and the end of the string, respectively.
• (.): Captures any single character (the parenthesis make it a group.)
• .*: Matches zero or more word characters (letters, digits, or underscores).Could also be a instead
• \1: Back reference to the first capturing group.

2. Contain a repeated pair of letters (e.g. “church” contains “ch” repeated twice.): (.)(.).*\1\2

• (.)(.): captures any two adjacent characters. Note for self: It’s not (..) because the letters don’t have to be the same
• .*: any characters in between
• \1\2: back references to the first two capturing groups, ensuring that what will be returned is any string that repeats a pair of adjacent characters and any characters in between.

3. Contain one letter repeated in at least three places (e.g. “eleven” contains three “e”s.): (.).\1.\1

• (.): captures any single character, could also be for a single word char.
• .*: represents anything in between
• \1: references back to the first group(any single character) and it’s in here twice to match any repeats that occur at least 3 times