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How do I match a word in regex?

How do I match a word in regex?

To run a “whole words only” search using a regular expression, simply place the word between two word boundaries, as we did with ‹ \bcat\b ›. The first ‹ \b › requires the ‹ c › to occur at the very start of the string, or after a nonword character.

Which regex matches the whole words dog or cat?

If we want to improve the first example to match whole words only, we would need to use \b(cat|dog)\b. This tells the regex engine to find a word boundary, then either cat or dog, and then another word boundary.

What is a word boundary regex?

A word boundary, in most regex dialects, is a position between \w and \W (non-word char), or at the beginning or end of a string if it begins or ends (respectively) with a word character ( [0-9A-Za-z_] ). So, in the string “-12” , it would match before the 1 or after the 2.

How do you match special characters in regex?

To match a character having special meaning in regex, you need to use a escape sequence prefix with a backslash ( \ ). E.g., \. matches “.” ; regex \+ matches “+” ; and regex \( matches “(” . You also need to use regex \\ to match “\” (back-slash).

How do you match a string in C#?

Using String. Compare

  1. string author1 = “Mahesh Chand”;
  2. string author2 = “Praveen Kumar”;
  3. // Use String.Compare method.
  4. if (String.Compare(author1, author2) == 0)
  5. Console.WriteLine($”Both strings have same value.”
  6. else if (String.Compare(author1, author2) < 0)
  7. Console.WriteLine($”{author1} precedes {author2}.”

What does \b do in C#?

C# – Character Escapes

Escape character Description Pattern
\b In a character class, matches a backspace, . [\b]{3,}
\t Matches a tab, . (\w+)\t
\r Matches a carriage return, . (\r is not equivalent to the newline character, \n.) \r\n(\w+)
\v Matches a vertical tab, . [\v]{2,}

What does \b do in regex?

Using regex – \bcat\b will match the word cat but not the cat in scattered . appears on your color – coded pass-key. Using regex \B-\B matches – between the word color – coded . Using \b-\b on the other hand matches the – in nine-digit and pass-key .

How do you check if a string contains a word in C#?

Use the Contains() method to check if a string contains a word or not.

What is \r in a string?

Just (invisible) entries in a string. \r moves cursor to the beginning of the line. \n goes one line down.

What is * in a RegEx?

Asterisk matches when the character preceding * matches 0 or more times. Note: * in RegEx is different from * in dtSearch. RegEx * is asking to find where the character (or grouping) preceding * is found ZERO or more times.

What is the differences between metacharacters and regular expressions?

Regular expressions are used for matching characters within text. Metacharacters are reserved symbols used to assist in matching.

What is the difference between * and *??

*? is non-greedy. * will match nothing, but then will try to match extra characters until it matches 1 , eventually matching 101 . All quantifiers have a non-greedy mode: . *? , .

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