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Copy a variable's value into another
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b = a;
The code actually does nothing at all, because a and b are the exact same thing. The code is the same as if you'd written:
b = b;
which obviously won't do anything.
Why does your new code work?
b = { key1: a.key1, key2: a.key2 };
Here you are creating a brand new object with the {....
Multi-line commands in GHCi
..., you can rely on type inference to work out a signature for you. In your example, the following is sufficient:
Prelude> let addTwo x y = x + y
If you really want a definition with a type signature, or your definition spans over multiple lines, you can do this in ghci:
Prelude> :{
Prelude|...
What is the strict aliasing rule?
... way, maybe get some warnings, have it compile fine, only to have weird unexpected behavior when you run the code.
(GCC appears somewhat inconsistent in its ability to give aliasing warnings, sometimes giving us a friendly warning and sometimes not.)
To see why this behavior is undefined, we have to...
is_null($x) vs $x === null in PHP [duplicate]
...e related isset() language construct checks whether the variable actually exists before doing the null check. So isset($undefinedVar) will not throw a notice.
Also note that isset() may sometimes return true even though the value is null - this is the case when it is used on an overloaded object, i...
Base64 encoding and decoding in client-side Javascript
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Some browsers such as Firefox, Chrome, Safari, Opera and IE10+ can handle Base64 natively. Take a look at this Stackoverflow question. It's using btoa() and atob() functions.
For server-side JavaScript (Node), you can use Buffers to decode.
If you are...
Random hash in Python
...ne:
import random
hash = random.getrandbits(128)
print("hash value: %032x" % hash)
I don't really see the point, though. Maybe you should elaborate why you need this...
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How do I pronounce “=>” as used in lambda expressions in .Net
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I usually say 'such that' when reading that operator.
In your example, p => p.Age > 16 reads as "P, such that p.Age is greater than 16."
In fact, I asked this very question on the official linq pre-release forums, and Anders Hejlsberg responded by saying
I usually read the =&g...
Check if list contains element that contains a string and get that element
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@JimIliadis "var" and "string" mean exactly the same thing in this case - the compiler is smart enough to know that the result can only be 'string'. var is really just a coding style thing (when not using anonymous types)
– Dave Bish
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Controlling mouse with Python
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Tested on WinXP, Python 2.6 (3.x also tested) after installing pywin32 (pywin32-214.win32-py2.6.exe in my case):
import win32api, win32con
def click(x,y):
win32api.SetCursorPos((x,y))
win32api.mouse_event(win32con.MOUSEEVENTF_LEF...
How to sort a list of strings?
...f the list, without changing the original, use the sorted() function:
for x in sorted(mylist):
print x
However, the examples above are a bit naive, because they don't take locale into account, and perform a case-sensitive sorting. You can take advantage of the optional parameter key to specif...