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Logical XOR operator in C++?
...sarily do what you might want for non-booleans. And as this is C++, there exists a real bool type instead of having to use int for that purpose.
– Greg Hewgill
Oct 20 '09 at 21:19
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Getting a better understanding of callback functions in JavaScript
...and passing in a function to another function as a callback and having it execute, but I'm not understanding the best implementation to do that. I'm looking for a very basic example, like this:
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'and' (boolean) vs '&' (bitwise) - Why difference in behavior with lists vs numpy arrays?
What explains the difference in behavior of boolean and bitwise operations on lists vs NumPy arrays?
8 Answers
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What is the string concatenation operator in Oracle?
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It is ||, for example:
select 'Mr ' || ename from emp;
The only "interesting" feature I can think of is that 'x' || null returns 'x', not null as you might perhaps expect.
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differences in application/json and application/x-www-form-urlencoded
... have on the server side. I see sites like stackoverflow & Twitter use x-www-form-urlencoded for AJAX requests like vote etc. The response sent back is JSON. I would think that it's better to have a symmetrical request/response pair i.e. both JSON.
– user
J...
What is tail recursion?
...learn lisp, I've come across the term tail-recursive . What does it mean exactly?
28 Answers
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object==null or null==object?
... left side of == isn't really useful in Java since Java requires that the expression in an if evaluate to a boolean value, so unless the constant is a boolean, you'd get a compilation error either way you put the arguments. (and if it is a boolean, you shouldn't be using == anyway...)
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Filter dict to contain only certain keys?
...of any size. Both in terms of speed and memory. Since this is a generator expression, it processes one item at a time, and it doesn't looks through all items of old_dict.
Removing everything in-place:
unwanted = set(keys) - set(your_dict)
for unwanted_key in unwanted: del your_dict[unwanted_key]
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Retrieve the position (X,Y) of an HTML element relative to the browser window
I want to know how to get the X and Y position of HTML elements such as img and div in JavaScript relative to the browser window.
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What's the correct way to convert bytes to a hex string in Python 3?
What's the correct way to convert bytes to a hex string in Python 3?
9 Answers
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