PHP Level 2, Regular Expressions
This quiz is a test of basic PCRE, aka, preg_match(). Difficult concepts in regexes are not covered. Passing the test indicates that you have a basic understanding of regexes.
- 1.
In the following statement, what does the "+" symbol mean?preg_match('/^[0-9]+$/', $data)
- A.
Any character
- B.
One character between 0 and 9
- C.
One or more characters between 0 and 9
- D.
Zero or more characters between 0 and 9
- E.
Any character between 0 and 9 followed by a $
Correct Answer
C. One or more characters between 0 and 9Explanation
The "+" symbol in the given statement means that there should be one or more characters between 0 and 9. This means that the regular expression will match any string that consists of one or more digits from 0 to 9.Rate this question:
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- 2.
What would match the regex in the following statement:preg_match('/^[0-9]{3}-[0-9]{2,4}$/', $data)
- A.
98090
- B.
213-99
- C.
415
- D.
1-2345
- E.
5-99
Correct Answer
B. 213-99Explanation
The given regular expression '/^[0-9]{3}-[0-9]{2,4}$/' matches strings that have the following pattern: three digits followed by a hyphen, followed by two to four digits. Therefore, the only string that matches this pattern is "213-99".Rate this question:
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- 3.
Rank these three function in the order of their typical speed, slowest to fastest: preg_match(), strpos(), ereg().
- A.
Preg_match, strpos, ereg
- B.
Ereg, preg_match, strpos
- C.
Ereg, strpos, preg_match
- D.
Preg_match, ereg, strpos
Correct Answer
B. Ereg, preg_match, strposExplanation
strpos is fastest.Rate this question:
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- 4.
How long is the shortest string that would match this regex:preg_match('/^[a-z]+[0-9]*[A-Z]{2,10}$/')
- A.
0 characters (empty string)
- B.
1 character
- C.
2 characters
- D.
3 characters
- E.
4 characters
Correct Answer
D. 3 charactersExplanation
The given regular expression requires a string that starts with one or more lowercase letters ([a-z]+), followed by zero or more digits ([0-9]*), and ends with 2 to 10 uppercase letters ([A-Z]{2,10}). In order to match this pattern, the string needs to have at least one lowercase letter, zero digits, and two uppercase letters. Therefore, the shortest string that would match this regex is "aAA", which has 3 characters.Rate this question:
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- 5.
What is the value of $matches[1]?preg_match('/([0-9]{3})-([0-9]{3})-([0-9]{4})/', "TEL 323-555-1212", $matches);
- A.
TEL
- B.
323
- C.
555
- D.
1212
Correct Answer
B. 323Explanation
The value of $matches[1] is 323. This is because the preg_match function is used to search for a pattern in a string. In this case, the pattern is defined as '/([0-9]{3})-([0-9]{3})-([0-9]{4})/'. The string "TEL 323-555-1212" is searched for this pattern. The pattern consists of three groups, each enclosed in parentheses. The first group ([0-9]{3}) matches three digits, the second group matches another three digits, and the third group matches four digits. The matched values are stored in the $matches array, with $matches[1] representing the first group. Therefore, the value of $matches[1] is 323.Rate this question:
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- 6.
Which of the following is NOT a typical use for regular expressions in pHP.
- A.
Validating input data
- B.
Dividing input text into substrings.
- C.
Converting hexadecimal into decimal.
- D.
Replacing strings with other strings.
Correct Answer
C. Converting hexadecimal into decimal.Explanation
Regular expressions in PHP are commonly used for validating input data, dividing input text into substrings, and replacing strings with other strings. However, converting hexadecimal into decimal is not a typical use for regular expressions in PHP. This task can be accomplished using built-in PHP functions or algorithms specifically designed for conversion between number systems.Rate this question:
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Aug 18, 2023Quiz Edited by
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Oct 15, 2009Quiz Created by
Johnkawakami
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