Regular expression: Write a regular expression to match patterns in the following strings. Demonstratethatyourregularexpressionindeedmatchedthatpatternbyincludingcodesandresults. Carefully review how the rst problem is solved for you.

a. In the following text, replace all the words that are exactly 3 or 4 characters long with triple dots ...

myText <- "Each of the three and four character words will be gone now"

b. Extract all the three numbers embedded in the following text.

bigText <- 'There were three 20@14 numbers hidden in 500 texts'

c. Extract all the words between parenthesis from the following string text and count number of words.

myText <- 'The salries are reported (in millions) for every companies.'

d. Extract the texts in between _ and dot(.) in the following vector. Your output should be bill, pay, ne-book.

myText <- c("H_bill.xls", "Big_H_pay.xls", "Use_case_fine-book.pdf")