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How can i tell if an object has a key value observer attached
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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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How do I count the number of occurrences of a char in a String?
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The loop method is much faster than this. Especially when wanting to count a char instead of a String (since there is no String.replace(char, char) method). On a 15 character string, I get a difference of 6049 ns vs 26,739 ns (averaged over 100runs). Raw numbers are huge...
Is there a way to automate the android sdk installation?
Now I have to download and install the Android SDK and AVD Manager, and then install the APIs, tools through the UI. Is there a way to automate this process?
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'Incomplete final line' warning when trying to read a .csv file into R
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Are you really sure that you selected the .csv file and not the .xls file? I can only reproduce the error if I try to read in an .xls file. If I try to read in a .csv file or any other text file, it's impossible to recreate the error y...
setuptools: package data folder location
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alexsmail
5,26377 gold badges3232 silver badges5252 bronze badges
answered Oct 23 '14 at 17:31
polvoazulpolvoazul
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Python Linked List
...le to reference separate parts of them. Make them immutable and they are really easy to work with!
28 Answers
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How long do browsers cache HTTP 301s?
...'s cache can accommodate it. It will be removed from the cache if you manually clear the cache, or if the cache entries are purged to make room for new ones.
You can verify this at least in Firefox by going to about:cache and finding it under disk cache. It works this way in other browsers includi...
TypeError: 'NoneType' object is not iterable in Python
... Correct, But the common scenario author intended here is totally to skip the for loop instead of raising an exception. Python's design is flawed here. When None is treated as an iterable it must return empty list at least. This exception never helped anyone in real life other than m...
“You have mail” message in terminal, os X [closed]
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and then type "d *" to erase all messages
– Ricardo Martins
Mar 20 '17 at 12:23
9
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Java dynamic array sizes?
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No you can't change the size of an array once created. You either have to allocate it bigger than you think you'll need or accept the overhead of having to reallocate it needs to grow in size. When it does you'll have to allocate a new one and copy the data from the old to the new:
int[] oldItems ...