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Get ID of last inserted document in a mongoDB w/ Java driver
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It's safe to do
doc.set("_id", new ObjectId())
if you look at driver code
if ( ensureID && id == null ){
id = ObjectId.get();
jo.put( "_id" , id );
}
public static ObjectId get(){
return new ObjectId();
}
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What is the python keyword “with” used for? [duplicate]
...resource is "cleaned up" when the code that uses it finishes running, even if exceptions are thrown. It provides 'syntactic sugar' for try/finally blocks.
From Python Docs:
The with statement clarifies code that previously would use try...finally blocks to ensure that clean-up code is executed. In ...
How to initialize a private static const map in C++?
...;< A::myMap[1]; into main(). It gives an error. The error doesn't occur if I remove the const qualifiers, so I guess map's operator[] can't handle a const map, at least, not in the g++ implementation of the C++ library.
– Craig McQueen
Oct 31 '13 at 1:08
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node.js: read a text file into an array. (Each line an item in the array.)
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+1 There some problem in Stackoverflow. Now, I often find highly voted answers after scrolling down by too far. This is also an example of this. It has highest voting but positioned at the bottom of the page, very last. I think Stackoverflow needs to improve their ...
How many concurrent AJAX (XmlHttpRequest) requests are allowed in popular browsers?
...crease the number of concurrent connections is to host your images from a different sub domain. These will be treated as separate requests, each domain is what will be limited to the concurrent maximum.
IE6, IE7 - have a limit of two. IE8 is 6 if you have a broadband - 2 (if it's a dial up).
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How to do scanf for single char in C [duplicate]
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Now that's wild! Would you explain why the space in front of %c makes a difference?
– Max Coplan
Sep 10 '19 at 15:59
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Is it possible to declare two variables of different types in a for loop?
Is it possible to declare two variables of different types in the initialization body of a for loop in C++?
8 Answers
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Passing a 2D array to a C++ function
...dimension(s). These are more flexible than the above ones since arrays of different lengths can be passed to them invariably.
It is to be remembered that there's no such thing as passing an array directly to a function in C [while in C++ they can be passed as a reference (1)]; (2) is passing a point...
How to trigger event when a variable's value is changed?
...of 1 then a certain piece of code is carried out.
I know that I can use an if statement but the problem is that the value will be changed in an asynchronous process so technically the if statement could be ignored before the value has changed.
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Count the number occurrences of a character in a string
...nswers said, using the string method count() is probably the simplest, but if you're doing this frequently, check out collections.Counter:
from collections import Counter
my_str = "Mary had a little lamb"
counter = Counter(my_str)
print counter['a']
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