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How to update PATH variable permanently from Windows command line?
... do this can be found on MSDN. The key extract is this:
To programmatically add or modify system environment variables, add them to the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment registry key, then broadcast a WM_SETTINGCHANGE message with lParam set to the s...
Turning a string into a Uri in Android
...ourse if there are any spaces in the string you pass in your app will barf all over the place if you launch an Intent with this Uri.
– Christopher Perry
Aug 9 '13 at 22:08
add...
What does LINQ return when the results are empty
I have a question about LINQ query. Normally a query returns a IEnumerable<T> type. If the return is empty, not sure if it is null or not. I am not sure if the following ToList() will throw an exception or just a empty List<string> if nothing found in IEnumerable result?
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What is the volatile keyword useful for?
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volatile has semantics for memory visibility. Basically, the value of a volatile field becomes visible to all readers (other threads in particular) after a write operation completes on it. Without volatile, readers could see some non-updated value.
To answer your question: Y...
How to select an element inside “this” in jQuery?
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does find only return the first occurance or all the occurances?
– Vignesh S
Nov 23 '16 at 17:58
add a comment
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When should I use nil and NULL in Objective-C?
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technically, they are exactly equal, you can send messages to both nil and to NULL. Idiomatically though nil is usually used to represent an object
– cobbal
Oct 14 '09 at 5:43
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In a Django form, how do I make a field readonly (or disabled) so that it cannot be edited?
...hanged his example to work with Django 1.3, using get_readonly_fields.
Usually you should declare something like this in app/admin.py:
class ItemAdmin(admin.ModelAdmin):
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readonly_fields = ('url',)
I've adapted in this way:
# In the admin.py file
class ItemAdmin(admin.ModelAdmin):
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Why doesn't the example compile, aka how does (co-, contra-, and in-) variance work?
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Generically, a covariant type parameter is one which is allowed to vary down as the class is subtyped (alternatively, vary with subtyping, hence the "co-" prefix). More concretely:
trait List[+A]
List[Int] is a subtype of List[A...
Why is __dirname not defined in node REPL?
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Yeah, that should really be added to the answer Eye, because that's what got me.
– Tomáš Zato - Reinstate Monica
Oct 12 '15 at 17:14
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How do you calculate the average of a set of circular data? [closed]
... sum_i_from_1_to_N cos(a[i])
The method given by starblue is computationally equivalent, but his reasons are clearer and probably programmatically more efficient, and also work well in the zero case, so kudos to him.
The subject is now explored in more detail on Wikipedia, and with other uses, l...