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Declaring an unsigned int in Java
...on is that most operations (such as addition, subtraction, multiplication, and left shift) are identical on a binary level for signed and unsigned integers. A few operations (division, right shift, comparison, and casting), however, are different. As of Java SE 8, new methods in the Integer class al...
Extract subset of key-value pairs from Python dictionary object?
...bigdict.get(k, None) for k in ('l', 'm', 'n')}
If you're using Python 3, and you only want keys in the new dict that actually exist in the original one, you can use the fact to view objects implement some set operations:
{k: bigdict[k] for k in bigdict.keys() & {'l', 'm', 'n'}}
...
How can I convert byte size into a human-readable format in Java?
...osted here was the most copied Java snippet of all time on Stack Overflow, and it was flawed. It was fixed, but it got messy.
Full story in this article: The most copied Stack Overflow snippet of all time is flawed!
Source: Formatting byte size to human readable format | Programming.Guide
SI (1 k =...
What's the opposite of head? I want all but the first N lines of a file
...
@Nicholas: Weird, I figured it would be standard documentation regardless of the OS. I pulled that from Cygwin inside Windows, so I don't know what it looks like in various Linux distros. Glad it worked.
– Joe Enos
Aug 18 '10 ...
Passing Objects By Reference or Value in C#
... have always thought that non-primitive variables were passed by reference and primitive values passed by value.
7 Answers
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Values of disabled inputs will not be submitted
...support the disabled attribute: BUTTON, INPUT,
OPTGROUP, OPTION, SELECT, and TEXTAREA.
This attribute is inherited but local declarations override the
inherited value.
How disabled elements are rendered depends on the user agent. For
example, some user agents "gray out" disabled menu...
“PKIX path building failed” and “unable to find valid certification path to requested target”
...got an error about certificate sun.security.validator.ValidatorException and sun.security.provider.certpath.SunCertPathBuilderException . Then I added twitter certificate by:
...
How many threads can a Java VM support?
... OS, on what other processes are doing, on what Java release you're using, and other factors. I've seen a Windows server have > 6500 Threads before bringing the machine down. Most of the threads were not doing anything, of course. Once the machine hit around 6500 Threads (in Java), the whole m...
How can I see the assembly code for a C++ program?
... the GNU assembler, compiling with -g -Wa,-alh will give intermixed source and assembly on stdout (-Wa asks compiler driver to pass options to assembler, -al turns on assembly listing, and -ah adds "high-level source" listing):
g++ -g -c -Wa,-alh foo.cc
For Visual Studio, use /FAsc.
Peek into the...
How do I check whether a file exists without exceptions?
...open_it(), it's safer to use a try around the attempt to open it. Checking and then opening risks the file being deleted or moved or something between when you check and when you try to open it.
If you're not planning to open the file immediately, you can use os.path.isfile
Return True if path ...