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Purpose of returning by const value? [duplicate]
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In the hypothetical situation where you could perform a potentially expensive non-const operation on an object, returning by const-value prevents you from accidentally calling this operation on a temporary. Imagine that + returned a non-const value, and you could write:
(a + b).expensiv...
Import error: No module name urllib2
...ython 3 named urllib.request and urllib.error. The 2to3 tool will automatically adapt imports when converting your sources to Python 3.
So you should instead be saying
from urllib.request import urlopen
html = urlopen("http://www.google.com/").read()
print(html)
Your current, now-edited code sa...
Convert string to variable name in JavaScript
...ontext. this is context, what it points to depends on how the function is called. In JS, 50% of the time this is window unless you enable strict mode and this becomes undefined and will throw an error. Scope is something completely different and it's not an object (except global scope which is mirro...
Printing hexadecimal characters in C
... signed on your system. In C, vararg functions such as printf will promote all integers smaller than int to int. Since char is an integer (8-bit signed integer in your case), your chars are being promoted to int via sign-extension.
Since c0 and 80 have a leading 1-bit (and are negative as an 8-bit ...
Get all object attributes in Python? [duplicate]
Is there a way to get all attributes/methods/fields/etc. of an object in Python?
4 Answers
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How does __proto__ differ from constructor.prototype?
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I've been trying to wrap my head around this recently and finally came up with this "map" that I think sheds full light over the matter
http://i.stack.imgur.com/KFzI3.png
I know I'm not the first one making this up but it was more interesting figuring it out that finding it :-). An...
Solving “Who owns the Zebra” programmatically?
...ution in Python based on constraint-programming:
from constraint import AllDifferentConstraint, InSetConstraint, Problem
# variables
colors = "blue red green white yellow".split()
nationalities = "Norwegian German Dane Swede English".split()
pets = "birds dog cats horse zebra".sp...
CSS: 100% font size - 100% of what?
...he percent-value is supposed to be. I understand this is 'the same size in all browsers'. I also read this, for instance:
9...
What is the difference between an IntentService and a Service? [duplicate]
...as Intents) on demand. Clients send requests through startService(Intent) calls; the service is started as needed, handles each Intent in turn using a worker thread, and stops itself when it runs out of work.
Refer this doc - http://developer.android.com/reference/android/app/IntentService.html
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Does JavaScript have a built in stringbuilder class?
... strings with the + or += operator are extremely slow on IE. This is especially true for IE6. On modern browsers += is usually just as fast as array joins.
When I have to do lots of string concatenations I usually fill an array and don't use a string builder class:
var html = [];
html.push(
"&l...