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PHP Regex to check date is in YYYY-MM-DD format

... Try this. $date="2012-09-12"; if (preg_match("/^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/",$date)) { return true; } else { return false; } ...
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How to know what the 'errno' means?

...) , I get an errno=2 . What does it mean? How can I know the meaning of this errno ? 15 Answers ...
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PHP validation/regex for URL

... I used this on a few projects, I don't believe I've run into issues, but I'm sure it's not exhaustive: $text = preg_replace( '#((https?|ftp)://(\S*?\.\S*?))([\s)\[\]{},;"\':<]|\.\s|$)#i', "'<a href=\"$1\" target=\"_blank\"&...
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Repeat Character N Times

... These days, the repeat string method is implemented almost everywhere. (It is not in Internet Explorer.) So unless you need to support older browsers, you can simply write: "a".repeat(10) Before repeat, we used this hack: Array(11).join("a") // create string...
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Why should I prefer single 'await Task.WhenAll' over multiple awaits?

... should I still use await Task.WhenAll instead of multiple await ? e.g, is DoWork2 below a preferred method to DoWork1 (and why?): ...
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How do I show multiple recaptchas on a single page?

I have 2 forms on a single page. One of the forms has a recaptcha displaying all the time. The other should display a recaptcha only after a certain event such as maxing out login attempts. So there are times when I would need 2 recaptchas to appear on the same page. Is this possible? I know I ...
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How to use concerns in Rails 4

... So I found it out by myself. It is actually a pretty simple but powerful concept. It has to do with code reuse as in the example below. Basically, the idea is to extract common and / or context specific chunks of code in order to clean up the models and avo...
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How can I override the OnBeforeUnload dialog and replace it with my own?

...on() { return 'You have unsaved changes!'; } Here's a reference to this from Microsoft: When a string is assigned to the returnValue property of window.event, a dialog box appears that gives users the option to stay on the current page and retain the string that was assigned to it. The def...
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difference between primary key and unique key

...able In some DBMS it cannot be NULL - e.g. MySQL adds NOT NULL Primary Key is a unique key identifier of the record Unique Key: Can be more than one unique key in one table Unique key can have NULL values It can be a candidate key Unique key can be NULL ; multiple rows can have NULL values and t...
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How can I distinguish whether Switch,Checkbox Value is changed by user or programmatically (includin

How to implement method isNotSetByUser() ? 16 Answers 16 ...