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How do I test which class an object is in Objective-C?
... an instance of a particular class in Objective-C? Let's say I want to see if object a is an instance of class b, or class c, how do I go about doing it?
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C# switch statement limitations - why?
...use it is wrong:
The switch statement is not the same
thing as a big if-else statement.
Each case must be unique and evaluated
statically. The switch statement does
a constant time branch regardless of
how many cases you have. The if-else
statement evaluates each condition
until...
Deleting lines from one file which are in another file
...rather than patterns (in case you want remove the lines in a "what you see if what you get" manner rather than treating the lines in f2 as regex patterns).
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Properties vs Methods
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What is the difference in the internal implementation of a property vs a method. Is anything pushed into the call stack whenever a property is used? If not, how else is it handled?
– Praveen
Jul 17 '...
List submodules in a Git repository
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@IgorGanapolsky - you can print on the console, if you do cat .gitmodules in the repository root...
– sdaau
Sep 17 '15 at 11:56
1
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MIT vs GPL license [closed]
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It seems to me that the chief difference between the MIT license and GPL is that the MIT doesn't require modifications be open sourced whereas the GPL does.
True - in general. You don't have to open-source your changes if you're using GPL. You could modi...
How does “304 Not Modified” work exactly?
My guess, if it's generated by the browser:
2 Answers
2
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Check if value already exists within list of dictionaries?
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Here's one way to do it:
if not any(d['main_color'] == 'red' for d in a):
# does not exist
The part in parentheses is a generator expression that returns True for each dictionary that has the key-value pair you are looking for, otherwise False.
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HTML if image is not found
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If Default.jpg is not available you will end up in an endless loop. You should add a check if (this.src != 'Default.jpg')
– dehlen
Jul 7 '16 at 10:05
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Is Meyers' implementation of the Singleton pattern thread safe?
...11, it is thread safe. According to the standard, §6.7 [stmt.dcl] p4:
If control enters
the declaration concurrently while the variable is being initialized, the concurrent execution shall wait for completion of the initialization.
GCC and VS support for the feature (Dynamic Initialization ...