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Failure [INSTALL_FAILED_ALREADY_EXISTS] when I tried to update my application
...me here because I wanted to know whether adb install -r would remove first and then install or upgrade my app. Although adb's description is not very clear (-r: replace existing application), adb install -r does indeed upgrade your app and does not remove your app data. Therefore suitable to test up...
Objective-C class -> string like: [NSArray className] -> @“NSArray”
...ntime (the internals of the runtime are mostly hidden from the application and exposed only through a few API functions). Each class object (e.g. [NSArray class]) is actually a struct. The struct contains a lot of information about the class, including its name, the methods it implements, the superc...
Why is there a difference in checking null against a value in VB.NET and C#?
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VB.NET and C#.NET are different languages, built by different teams who have made different assumptions about usage; in this case the semantics of a NULL comparison.
My personal preference is for the VB.NET semantics, which in esse...
Break when a value changes using the Visual Studio debugger
Is there a way to place a watch on variable and only have Visual Studio break when that value changes?
13 Answers
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Simplest/Cleanest way to implement singleton in JavaScript?
...ake the object immutable, preventing any modification to the its structure and values.
Additionally I would like to mention that if you are using ES6, you can represent a singleton using ES Modules very easily, and you can even hold private state by declaring variables at the module scope:
// my-s...
How do I provide custom cast support for my class?
...ypes? For example, if I have my own implementation of managing a byte[] , and I want to let people cast my class to a byte[] , which will just return the private member, how would I do this?
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Android: how do I check if activity is running?
...the same class running? What if you extend MyActivity with MyChildactivity and want to check if the child is active?
– Mister Smith
Sep 2 '13 at 10:27
2
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Is it sometimes bad to use ?
...ments, for example <p>Stuff</p><p>Other stuff</p>, and then using CSS to space the blocks out properly.
There are cases where <br> is semantically valid, i.e. cases where the line break is part of the data you're sending. This is really only limited to 2 use cases - po...
What's the most appropriate HTTP status code for an “item not found” error page
...t ambiguous for differentiating a bad URI versus entity not found. A new standard code is needed to disambiguate 404s.
– Breakskater
Mar 7 '19 at 16:45
3
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What exactly does the Access-Control-Allow-Credentials header do?
I'm trying to understand how to use CORS and am confused about what the Access-Control-Allow-Credentials header does.
1 A...