ADV PROG REGEX

Question 1

is used to turn off (escape) the special meaning of a meta-character or to confer special meaning to other characters.

Answer 1

Backslash ( ), known as the escape character

Question 2

is a list of values placed inside square braces to match a single character in data.

Answer 2

character class([ ] )

caret ( ^) negates the list inside the brackets

Question 3

[0-9]

Any digit character

Answer 3

\d

Question 4

[^0-9]

Any non-digit character

Answer 4

\D

Question 5

[A-Za-z0-9_]

Any word character

Answer 5

\w

Question 6

[^A-Za-z0-9_]

Any non-word character

Answer 6

\W

Question 7

[\t\r\n\f ]

Any whitespace character

Answer 7

\s

Question 8

[^\t\r\n\f ]

Any non-whitespace character

Answer 8

\S

Question 9

is either a single character or a group of related characters.

Answer 9

token

Question 10

used to indicate how many times the previous token should be repeated.

Answer 10

quantifier({ } )

Question 11

{0,}

Zero or more of the previous token

Answer 11

*

Question 12

{1,}

One or more of the previous token

Answer 12

+

Question 13

{0,1}

Zero or one of the previous token

Answer 13

?

Question 14

used to match the start of a string, except when part of a character class.

Answer 14

caret ( ^ )

Question 15

used to match the end of a string.

Answer 15

dollar sign ( $ )

Question 16

used to match a zero-length position before or after a word character, effectively matching whole words only anywhere in a line of text.

Answer 16

boundary anchor ( \b )

Question 17

used to match any single character, except .

Answer 17

dot (. )

Question 18

used to make a group of tokens that can be quantified as a unit or to create a list of string values from which to choose.

Answer 18

back references(\1 … \9)

Question 19

used in a group to create a selection of strings from which to choose, thereby matching either token on the left or right side.

Answer 19

pipe ( | )