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Regular Expressions: Difference between revisions
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You can test regular expressions online at [https://regex101.com/]. | You can test regular expressions online at [https://regex101.com/]. | ||
==Syntax== | |||
===Letters=== | |||
<code>[a-zA-Z]</code> | |||
===Numbers=== | |||
You should match numbers using <code>[0-9]</code>.<br> | |||
<code>\d</code> will match unicode characters which are classified as digits.<br> | |||
See [https://stackoverflow.com/questions/890686/should-i-use-d-or-0-9-to-match-digits-in-a-perl-regex \d vs 0-9] | |||
==Useful Regular Expressions== | ==Useful Regular Expressions== | ||
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Capturing significand and exponent separately. | Capturing significand and exponent separately. | ||
<syntaxhighlight lang="ragel"> | <syntaxhighlight lang="ragel"> | ||
([-+]? | ([-+]?[0-9]*\.?[0-9]+)(?:[eE]([-+]?[0-9]+))? | ||
</syntaxhighlight> | </syntaxhighlight> | ||
Capturing the entire string together. | Capturing the entire string together. | ||
<syntaxhighlight lang="ragel"> | <syntaxhighlight lang="ragel"> | ||
([-+]? | ([-+]?[0-9]*\.?[0-9]+(?:[eE][-+]?[0-9]+)?) | ||
</syntaxhighlight> | </syntaxhighlight> | ||