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How can i tell if an object has a key value observer attached

... Put a try catch around your removeObserver call @try{ [someObject removeObserver:someObserver forKeyPath:somePath]; }@catch(id anException){ //do nothing, obviously it wasn't attached because an exception was thrown } ...
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Creating Unicode character from its number

... So you need to be absolutely sure ahead of time that your value of c is smaller than 0x10000, or else this approach will break horribly. – David Given Mar 13 '12 at 22:29 1 ...
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Proper way to make HTML nested list?

... same applies to HTML5 ol. The description list (HTML5 dl) is similar, but allows both dt and dd elements. More Notes: dl = definition list. ol = ordered list (numbers). ul = unordered list (bullets). share | ...
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Warning: mysql_connect(): [2002] No such file or directory (trying to connect via unix:///tmp/mysql.

...aybe good to mention: When using MAMP like me you have to uncheck the box "Allow local access only" – soupdiver Jan 21 '13 at 17:23 ...
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Check whether HTML element has scrollbars

... If overflow is visible or hidden, there usually are no scrollbars. – Hubert Grzeskowiak Jul 21 '16 at 18:27  |  ...
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What is a WeakHashMap and when to use it? [duplicate]

...hey are useful to save resource, you can keep a reference to something but allow it to be collected when nothing else references it. (BTW, a strong reference is a normal java reference). There are also weak references which tend not to be as readily collected as soft references (which don't tend to...
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Javascript infamous Loop issue? [duplicate]

...one with data- attributes, or something like jQuery's .data(). These generally solve the problems in that article (e.g. data- is reserved for users, so a future standard will never define a data-something attribute). – Matthew Flaschen Mar 15 '14 at 4:20 ...
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How to check if a process id (PID) exists

...process is not owned by the running user, you may not have permissions to call kill -0. Better to use ps -p $PID > /dev/null 2>&1, which allows you to see process status, even if you do not have permissions to send a signal. – mckoss Apr 1 '12 at 16:...
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How to run the sftp command with a password from Bash script?

... Expect is a great program to use. On Ubuntu install it with: sudo apt-get install expect On a CentOS Machine install it with: yum install expect Lets say you want to make a connection to a sftp server and then upload a local file from your local machine to the remot...
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Visual Studio Solutions Folder as real Folders

...orst things about VS. Why don't MS keep Sln folders as an option, but ALSO allow REAL folders to be added to the solution. So annoying. The File System works, why reinvent the wheel (as a square). – MemeDeveloper Jul 24 at 13:55 ...