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What is null in Java?
...e inventor of null himself, C.A.R Hoare (of quicksort fame):
I call it my billion-dollar mistake. It was the invention of the null reference in 1965. At that time, I was designing the first comprehensive type system for references in an object oriented language (ALGOL W). My goal was to ensure t...
How do I verify that an Android apk is signed with a release certificate?
...< jdk < bin path in cmd prompt)
$ jarsigner -verify -verbose -certs my_application.apk
If you see "CN=Android Debug", this means the .apk was signed with the debug key generated by the Android SDK
(means it is unsigned), otherwise you will find something for CN.
For more details see: http:/...
How to use hex color values
...
This is my favorite implementation because of the way it handles the 3 cases. But I prefer the default: case to return nil, instead of white.
– Richard Venable
Mar 21 '16 at 13:54
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Calling virtual functions inside constructors
...constructor or Derived constructor. The implications are different (and to my likings more dangerous). If the base class constructor calls a method that is overriden in the derived class the call will actually be handled at the derived level calling a method on an unconstructed object, yielding unex...
Regex Named Groups in Java
It is my understanding that the java.regex package does not have support for named groups ( http://www.regular-expressions.info/named.html ) so can anyone point me towards a third-party library that does?
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float:left; vs display:inline; vs display:inline-block; vs display:table-cell;
...ack for the broken support for inline-block.
display:inline-block;
This is my favourite option. It works well and consistently across all browsers, with a caveat for IE6/7, which support it for some elements. But see above for the hacky solution to work around this.
The other big caveat with inlin...
Rails ActionMailer - format sender and recipient name/email address
...recipients = "\"#{user.name}\" <#{user.email}>"
@from = "\"MyCompany\" <info@mycompany.com>"
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Can I implement an autonomous `self` member type in C++?
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@dyp For the purpose of my answer that won’t change anything. The error here isn’t in the trailing return type, it’s in the invocation.
– Konrad Rudolph
Jan 15 '14 at 17:18
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How do you unit test private methods?
...w PrivateObject( objectInstanceToBeWrapped );
// Retrieve a private field
MyReturnType accessiblePrivateField = (MyReturnType) accessor.GetField( "privateFieldName" );
// Call a private method
accessor.Invoke( "PrivateMethodName", new Object[] {/* ... */} );
...
How to write a multidimensional array to a text file?
...that's not a primary concern, just pickle it.
To save it:
import pickle
my_data = {'a': [1, 2.0, 3, 4+6j],
'b': ('string', u'Unicode string'),
'c': None}
output = open('data.pkl', 'wb')
pickle.dump(my_data, output)
output.close()
To read it back:
import pprint, pickle
pk...