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match

match(r::Regex, s::AbstractString[, idx::Integer[, addopts]])

Search for the first match of the regular expression r in s and return a RegexMatch object containing the match, or nothing if the match failed. The matching substring can be retrieved by accessing m.match and the captured sequences can be retrieved by accessing m.captures The optional idx argument specifies an index at which to start the search.

Examples

1. Find the first match in a string:

   julia> regex = r"(\d+)";
   julia> text = "Julia version 1.6.0";
   julia> m = match(regex, text)
   RegexMatch("1", 1="1")

   This example searches for the first match of the regular expression (\d+) in the string text. It returns a RegexMatch object m containing the matched substring "1". The captured sequence can be accessed using m.match.

2. Access captured sequences:

   julia> regex = r"(\d+)-(\w+)";
   julia> text = "Date: 2022-08-01";
   julia> m = match(regex, text)
   RegexMatch("2022-01", 1="2022", 2="01")

   In this example, the regular expression (\d+)-(\w+) captures the date in the format yyyy-mm. The RegexMatch object m contains the matched substring "2022-01". The captured sequences can be accessed using m.captures.

3. Start the search from a specific index:

   julia> regex = r"[aeiou]";
   julia> text = "banana";
   julia> m = match(regex, text, 3)
   RegexMatch("a", 1="a")

   Here, the match starts from index 3 in the string "banana". The RegexMatch object m contains the first vowel "a".

Common mistake example:

julia> regex = r"(\d+)";
julia> text = "No numbers here";
julia> m = match(regex, text)
nothing

In this example, the regular expression (\d+) is used to search for numbers in a string that does not contain any. As a result, the match function returns nothing. Always ensure that the regular expression matches the expected pattern in the input string to avoid such situations.

See Also

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