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How do I compare strings in Java?
...th the safe navigation operator (groovy.codehaus.org/…), ?.. That would convert nullString1?.equals(nullString2); into an entirely null statement. However, it doesn't help if you have validString?.equals(nullString); -- that still throws an exception.
– Charles Wood
...
Node.js vs .Net performance
...n other platforms, but on Windows IIS is the winner. Developers looking to convert their ASP.NET MVC to nodejs should pause and think twice before proceeding.
Updated (5/17/2012)
Tomcat (on windows) seems to beat IIS hands down, about 3 times faster than IIS in dishing out static html.
tomcat
ind...
Where can I get a “useful” C++ binary search algorithm?
... T and the type after ForwardIt is dereferenced
// must be implicitly convertible to BOTH Type1 and Type2, used in Compare.
// This is stricter than lower_bound requirement (see above)
first = std::lower_bound(first, last, value, comp);
return first != last && !comp(value,...
Covariance and contravariance real world example
...) // "Melman"
};
PrintLifeForms(myGiraffes); // Compile Error!
cannot convert from 'System.Collections.Generic.List<Giraffe>' to 'System.Collections.Generic.IList<LifeForm>'
Why? Because the generic parameter IList<LifeForm> is not covariant -
IList<T> is invariant, s...
Android: Is it possible to display video thumbnails?
...this will work.
int id = **"The Video's ID"**
ImageView iv = (ImageView ) convertView.findViewById(R.id.imagePreview);
ContentResolver crThumb = getContentResolver();
BitmapFactory.Options options=new BitmapFactory.Options();
options.inSampleSize = 1;
Bitmap curThumb = MediaStore.Video.Thumbnails.g...
Where does Scala look for implicits?
...Int) = new A(n)
}
// This becomes possible:
1 + new A(1)
// because it is converted into this:
A.fromInt(1) + new A(1)
This is available since Scala 2.9.1.
Implicit Scope of Type Arguments
This is required to make the type class pattern really work. Consider Ordering, for instance: It comes wit...
Determine a string's encoding in C#
...ou are reading the contents of a file, which is made of bytes, and wish to convert that to a string, then the file's encoding must be used.
.NET includes encoding and decoding classes for: ASCII, UTF7, UTF8, UTF32 and more.
Most of these encodings contain certain byte-order marks that can be used ...
adding noise to a signal in python
...et SNR
# Set a target SNR
target_snr_db = 20
# Calculate signal power and convert to dB
sig_avg_watts = np.mean(x_watts)
sig_avg_db = 10 * np.log10(sig_avg_watts)
# Calculate noise according to [2] then convert to watts
noise_avg_db = sig_avg_db - target_snr_db
noise_avg_watts = 10 ** (noise_avg_d...
GUI not working after rewriting to MVC
...plicity.
A more common approach uses an EventListenerList, as shown in the Converter application and suggested by the large number of EventListener subinterfaces and implementing classes.
A third option is to use a PropertyChangeListener, as shown here and here.
Addendum: Some common questions abo...
Efficient Algorithm for Bit Reversal (from MSB->LSB to LSB->MSB) in C
... printf ("\r\n");
}
printf ("\r\nNumber of 32-byte chunks to convert: %d\r\n",(unsigned int)ceil(NUM_DATA_BYTES/32.0));
double start_time = omp_get_wtime();
bitflipbyte(data,(unsigned int)ceil(NUM_DATA_BYTES/32.0),k1);
double end_time = omp_get_wtime();
printf ("\r\nD...