Given the following regular expression:
.* 14203+(21870110458)
Which two AS paths match? (Choose two.)
A.
27522 2187010458
B.
27522 14203 14203 14203 21870
C.
14203 21780 10458
D.
14203 21780 27522
Explanation:
Which two AS paths match?
Given the following regular expression:
.* 14203+(21870110458)
Which two AS paths match? (Choose two.)
If the regular expression is: .* 14203+ (21870|10458) and there’s a pipe “|” between 21870 and 10458, then answer B and D.
Correction: answer b and c
I also agree. B and C are correct
Definitions
. ==> One instance of any character except the space. For example, .456 matches 1456 or 6456.
+ ==> One or more instances of the immediately preceding term. For example, tre+ matches messages with tree or tread but not trough.
* ==> Zero or more instances of the immediately preceding term. For example, 234* matches 2345698 or 2347985
.*14203+ (21870 | 10458)
(.) Can begin with one instance of any character except space. Meaning it can begin with anything.
The Any Characters we chose in (*) is preceeding (*)
What determines the answer are these
Must have one or more instances of 14203 (Makes answer A wrong)
Then can have either 21870 or 10458 at the end (Makes answer D wrong)
It should be: .* 14203+ (21870|10458)$ and therefore B and C are correct.
with all the possibilities mentioned I tried but all fails. no match .http://www.regexplanet.com/advanced/java/index.html
D is also incorrect as it doesn’t end with either 21870 or 10458. Only C is correct and matches.
I’m smoking crack.
B is the only correct answer.
C ends with both 21870 and 10458. The “()” is an OR operator. It can’t match both.
by playing left and right the only option gets the two results is:
.* 14203+ (21870|10458)$
selecting three options:
1.Perform multiline matching
2. Perform a global match (don’t stop at first match)
3. DOT ALL. The dot (.) metacharacter matches any character INCLUDING line breaks.
answer A & B
A: 27522 2187010458
B: 27522 14203 14203 14203 21870
http://www.freeformatter.com/regex-tester.html