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Swift: declare an empty dictionary
...ou have to be explicit, otherwise you will produce an unusable instance of __NSDictionaryI. Try adding an element to that emptyDict and it will fail at compile time.
– Gabriele Petronella
Jun 4 '14 at 13:34
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Selectors in Objective-C?
First, I'm not sure I really understand what a selector is. From my understanding, it's the name of a method, and you can assign it to a class of type 'SEL' and then run methods such as respondToSelector to see if the receiver implements that method. Can someone offer up a better explanation?
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What is the meaning of the planned “private protected” C# access modifier?
As part of the Roslyn documentation on GitHub, there's a page called Language feature implementation status , with planned language features for C# and VB.
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Javascript: How to loop through ALL DOM elements on a page?
I'm trying to loop over ALL elements on a page, so I want to check every element that exists on this page for a special class.
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Overriding a JavaScript function while referencing the original
...tioned in the comments, be sure to include the () at the end. You want to call the outer function and store the result (one of the two inner functions) in a, not store the outer function itself in a.
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Javascript when to use prototypes
...ods, over and over.
Instead, those methods are defined on a prototype and all jQuery objects "inherit" that prototype so as to gain all those methods at very little runtime cost.
One vitally important part of how jQuery gets it right is that this is hidden from the programmer. It's treated purely ...
Prevent the keyboard from displaying on activity start
...g both in code, and in xml! Indeed, this is the most correct answer! Especially since it was probably that 3 minutes you spent writing both methods that made you not first ;-)
– eric
Apr 21 '17 at 1:13
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Angularjs ng-model doesn't work inside ng-if
...rent.foo because I'm already inside a scope with an ng-repeat -- is this really the best way?
– chovy
Nov 25 '13 at 3:58
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Reloading submodules in IPython
...atic reloading magic:
%load_ext autoreload
%autoreload 2
It will reload all changed modules every time before executing a new line. The way this works is slightly different than dreload. Some caveats apply, type %autoreload? to see what can go wrong.
If you want to always enable this settings,...
Pass a data.frame column name to a function
...l_name,col1,col2){
df$col_name <- df$col1 + df$col2
df
}
#Call foo() like this:
foo(dat,z,x,y)
The problem here is that df$col1 doesn't evaluate the expression col1. It simply looks for a column in df literally called col1. This behavior is described in ?Extract under the secti...