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SQL is null and = null [duplicate]
...considered as false for the purposes of a where clause (strictly speaking, it's "not true", rather than "false", but the effect is the same).
The reasoning is that a null means "unknown", so the result of any comparison to a null is also "unknown". So you'll get no hit on rows by coding where my_co...
Does adding a duplicate value to a HashSet/HashMap replace the previous value
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In the case of HashMap, it replaces the old value with the new one.
In the case of HashSet, the item isn't inserted.
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Is there a destructor for Java?
...ed. Hence there is no direct equivalent of a destructor.
There is an inherited method called finalize, but this is called entirely at the discretion of the garbage collector. So for classes that need to explicitly tidy up, the convention is to define a close method and use finalize only for sanity ...
Forward declaring an enum in C++
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The reason the enum can't be forward declared is that without knowing the values, the compiler can't know the storage required for the enum variable. C++ Compiler's are allowed to specify the actual storage space based on the size necessary to contain all the values specified. ...
Is there any downside for using a leading double slash to inherit the protocol in a URL? i.e. src=“/
I have a stylesheet that loads images from an external domain and I need it to load from https:// from secure order pages and http:// from other pages, based on the current URL. I found that starting the URL with a double slash inherits the current protocol. Do all browsers support this technique?...
I lose my data when the container exits
Despite Docker's Interactive tutorial and faq I lose my data when the container exits.
11 Answers
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How do you print in Sublime Text 2
Sublime Text 2 seems like a great editor. I just started using it a week ago in eval mode and it doesn't seem to have any printing functionality. This seems preposterous to me, but I can't find it anywhere.
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How to run iPhone emulator WITHOUT starting Xcode?
On my old Mac running Snow Leopard, I could type "ios" into spotlight and it would start up the iPhone/iPad emulator by itself.
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Checking whether something is iterable
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The proper way to check for iterability is as follows:
function isIterable(obj) {
// checks for null and undefined
if (obj == null) {
return false;
}
return typeof obj[Symbol.iterator] === 'function';
}
Why this works (iterable protocol i...
Release generating .pdb files, why?
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Because without the PDB files, it would be impossible to debug a "Release" build by anything other than address-level debugging. Optimizations really do a number on your code, making it very difficult to find the culprit if something ...