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How to use a variable inside a regular expression?

... 10 Answers 10 Active ...
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Specifying column name in a “references” migration

... 61 Do it manually: add_column :post, :author_id, :integer but now, when you create the belongs_t...
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Getting visitors country from their IP

... +1350 Try this simple PHP function. <?php function ip_info($ip = NULL, $purpose = "location", $deep_detect = TRUE) { $output = N...
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Run Cron job every N minutes plus offset

...-59/20 * * * * Explanation An * in the minute field is the same as 0-59/1 where 0-59 is the range and 1 is the step. The command will run at the first minute in the range (0), then at all successive minutes that are distant from the first by step (1), until the last (59). Which is why */20 * * *...
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Choice between vector::resize() and vector::reserve()

... the only effect. So it depends on what you want. If you want an array of 1000 default items, use resize(). If you want an array to which you expect to insert 1000 items and want to avoid a couple of allocations, use reserve(). EDIT: Blastfurnace's comment made me read the question again and reali...
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RRSet of type CNAME with DNS name foo.com. is not permitted at apex in zone bar.com

... As per RFC1912 section 2.4: A CNAME record is not allowed to coexist with any other data. In other words, if suzy.podunk.xx is an alias for sue.podunk.xx, you can't also have an MX record for suzy.podunk.edu, or an A record, or e...
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What's best SQL datatype for storing JSON string?

... 199 Certainly NOT: TEXT, NTEXT: those types are deprecated as of SQL Server 2005 and should not ...
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How to do this using jQuery - document.getElementById(“selectlist”).value

... 150 $('#selectlist').val(); ...
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What is the “-->” operator in C++?

... | edited Dec 23 '18 at 15:46 community wiki ...
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Modifying a subset of rows in a pandas dataframe

... | edited Dec 3 '18 at 6:52 answered Sep 6 '12 at 19:37 ...