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Javascript - removing undefined fields from an object [duplicate]

... You actually don't even need the ternary operator. Instead you can do (obj[key]===undefined&& delete obj[key]) The reason this works is because and uses short-circuit evaluation, so once the first check fails the second isn'...
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How to get a cross-origin resource sharing (CORS) post request working

... I finally stumbled upon this link "A CORS POST request works from plain javascript, but why not with jQuery?" that notes that jQuery 1.5.1 adds the Access-Control-Request-Headers: x-requested-with header to all CORS requests....
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Should a return statement be inside or outside a lock?

...ock. Dangerous! – Torbjørn Feb 15 '10 at 14:37 @MarcGravell: I just came across your post while pondering the same an...
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How can I alter a primary key constraint using SQL syntax?

...y constraint name, use query found here to look it up (or look up and drop all at once). http://stackoverflow.com/a/13948609/945875 – Justin Dec 19 '13 at 20:06 ...
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How to make a phone call in android and come back to my activity when the call is done?

... 106 use a PhoneStateListener to see when the call is ended. you will most likely need to trigger ...
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To ARC or not to ARC? What are the pros and cons? [closed]

...t has no GC runtime overhead. The compiler inserts retains and releases in all the places you should have anyway. But it's smarter than you and can optimize out the ones that aren't actually needed (just like it can unroll loops, eliminate temporary variables, inline functions, etc.) OK, now I will...
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RegEx for Javascript to allow only alphanumeric

I need to find a reg ex that only allows alphanumeric. So far, everyone I try only works if the string is alphanumeric, meaning contains both a letter and a number. I just want one what would allow either and not require both. ...
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Error Dropping Database (Can't rmdir '.test\', errno: 17)

Basically, I was taught on how to create a root password using the "mysqladmin -u root -p password" command, this was done all through the windows command editor. Now, the next process was to display the default databases (info. schema, mysql and test) which was achieved by using "SHOW DATABASES;" ...
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Is “double hashing” a password less secure than just hashing it once?

...o compute a hash for each password and see if it matches the stored hash. All passwords are not equally likely. Attackers might exhaustively search all short passwords, but they know that their chances for brute-force success drop sharply with each additional character. Instead, they use an ordered...
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Explicitly select items from a list or tuple

...ray: >>> import numpy >>> myBigList = numpy.array(range(1000)) >>> myBigList[(87, 342, 217, 998, 500)] Traceback (most recent call last): File "<stdin>", line 1, in <module> IndexError: invalid index >>> myBigList[[87, 342, 217, 998, 500]] array([ 8...