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How can I be notified when an element is added to the page?

...he context of a browser extension, so the webpage runs independently of me and I cannot modify its source. What are my options here? ...
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Should each and every table have a primary key?

I'm creating a database table and I don't have a logical primary key assigned to it. So, I'm thinking about leaving it without a primary key, but I'm feeling a bit guilty about it. Should I? ...
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Python: how to print range a-z?

... Hints: import string print string.ascii_lowercase and for i in xrange(0, 10, 2): print i and "hello{0}, world!".format('z') share | improve this answer | ...
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How do I write a short literal in C++?

...ictly a short literal, more of a casted-int, but the behaviour is the same and I think there isn't a direct way of doing it. That's what I've been doing because I couldn't find anything about it. I would guess that the compiler would be smart enough to compile this as if it's a short literal (i....
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Can a java file have more than one class?

...can. However, there can only be one public top-level class per .java file, and public top-level classes must have the same name as the source file. The purpose of including multiple classes in one source file is to bundle related support functionality (internal data structures, support classes, etc...
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Is there any way to call a function periodically in JavaScript?

... I upvoted and then decided to rescind my upvote (but not downvote) because you are using a string argument to setInterval. Functions should almost always be used in favor of a string argument, for efficiency, security, and for their cl...
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Is there a PHP function that can escape regex patterns before they are applied?

... string $str [, string $delimiter = NULL ] ) preg_quote() takes str and puts a backslash in front of every character that is part of the regular expression syntax. This is useful if you have a run-time string that you need to match in some text and the string may contain special r...
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Why does the is operator return false when given null?

...e) type One would be implicitly assuming that a type is a set of values, and that assignment compatibility of a value y with a variable of type X is nothing more nor less than checking whether y is a member of set x. Though that is an extremely common way of looking at types, that is not the onl...
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Clearing intent

My Android app is getting called by an intent that is passing information (pendingintent in statusbar). 20 Answers ...
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How does lock work exactly?

...// body } finally { Monitor.Exit(temp); } In C# 4.0 this has changed and it is now generated as follows: bool lockWasTaken = false; var temp = obj; try { Monitor.Enter(temp, ref lockWasTaken); // body } finally { if (lockWasTaken) { Monitor.Exit(temp); } } You c...