Matching the regular expression special character with its purpose

[Splendid Digital Solutions]

Source: Created with help of AI tool

Match the regular expression special character with its purpose:

1. A single arbitrary character

The regular expression special character for matching a single arbitrary character is the dot (.).

For example:
– a.b matches any three-character string that starts with “a”, ends with “b”, and has any single character in between, such as “acb” or “a1b”.

2.  Arbitrarily many repetitions of the previous character or group but at least one occurrence

The regular expression special character for arbitrarily many repetitions of the previous character or group, but with at least one occurrence, is the plus sign (+).

For example:
– a+ matches one or more occurrences of the character ‘a’, such as “a”, “aa”, “aaa”, etc.
– (ab)+ matches one or more occurrences of the group “ab”, such as “ab”, “abab”, “ababab”, etc.

3. Arbitrarily many repetitions of the previous character or group including no occurrence

The regular expression special character for arbitrarily many repetitions of the previous character or group, including the possibility of no occurrence, is the asterisk (*).

For example:
– a* matches zero or more occurrences of the character ‘a’, including an empty string, “a”, “aa”, “aaa”, etc.
– (ab)* matches zero or more occurrences of the group “ab”, including an empty string, “ab”, “abab”, “ababab”, etc.

4. Zero or one occurrence of the previous character or group

The regular expression special character for zero or one occurrence of the previous character or group is the question mark (?).

For example:
– a? matches zero or one occurrence of the character ‘a’, so it would match an empty string or “a”.
– (abc)? matches zero or one occurrence of the group “abc”, meaning it would match either an empty string or the string “abc”.

5. The beginning of the string

The regular expression special character for matching the beginning of a string is the caret (^).

For example:
– ^abc matches any string that starts with “abc”, such as “abc123” but not “123abc”.

6. The end of the string

The regular expression special character for matching the end of a string is the dollar sign ($).

For example:
– abc$ matches any string that ends with “abc”, such as “123abc” but not “abc123”.

 

 

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