Questions & Results
Q1 of 10Multiple ChoiceAccuracy45s · 1 pt
Which string is fully matched by the regex (a|b)*c ?
165 / 178 answered · 88% correct
Q2 of 10Multiple ChoiceAccuracy45s · 1 pt
What does the regex ab* match?
A Any string of a's and b's B Zero or more copies of ab C An a followed by zero or more b's✓ Correct D Either a or zero or more b's 172 / 178 answered · 96% correct
Q3 of 10Multiple ChoiceAccuracy60s · 1 pt
Which regex describes exactly the strings over {a, b} with EVEN length?
175 / 178 answered · 92% correct
Q4 of 10Multiple ChoiceAccuracy45s · 1 pt
Which string is NOT in the language of a*b* ?
174 / 178 answered · 98% correct
Q5 of 10Multiple ChoiceAccuracy45s · 1 pt
Which regex is equivalent to a+ ?
176 / 178 answered · 95% correct
Q6 of 10Multiple ChoiceAccuracy60s · 1 pt
Which string is matched by ^[0-9]{3}-[0-9]{4}$ ?
175 / 178 answered · 98% correct
Q7 of 10Multiple ChoiceAccuracy60s · 1 pt
Which regex describes exactly the strings over {0, 1} that contain 11 as a substring?
A (0|1)*11(0|1)*✓ Correct 176 / 178 answered · 97% correct
Q8 of 10Multiple ChoiceAccuracy60s · 1 pt
The regex ([a-z]+)@([a-z]+).com is matched against alice@umd.com. What does capture group 2 contain?
178 / 178 answered · 95% correct
Q9 of 10Multiple ChoiceAccuracy60s · 1 pt
What substring does a.*b match in the string axbyb ?
176 / 178 answered · 64% correct
Q10 of 10Multiple ChoiceAccuracy60s · 1 pt
Which language CANNOT be described by any regular expression?
A { aⁿbⁿ | n ≥ 0 }✓ Correct B Strings over {a, b} of length at most 3 C Strings over {a, b} that end in ab D Strings over {a, b} with an even number of a's 178 / 178 answered · 81% correct
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