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How to check if an object is an array?
... {
Array.isArray = function(obj) {
return Object.prototype.toString.call(obj) === '[object Array]';
}
};
If you use jQuery you can use jQuery.isArray(obj) or $.isArray(obj). If you use underscore you can use _.isArray(obj)
If you don't need to detect arrays created in different frames you...
How to install psycopg2 with “pip” on Python?
I'm using virtualenv and I need to install "psycopg2".
33 Answers
33
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Is non-blocking I/O really faster than multi-threaded blocking I/O? How?
...ocking or asynchronous I/O is that your thread can continue its work in parallel. Of course you can achieve this also using an additional thread. As you stated for best overall (system) performance I guess it would be better to use asynchronous I/O and not multiple threads (so reducing thread switch...
Is it expensive to use try-catch blocks even if an exception is never thrown?
...
try has almost no expense at all. Instead of doing the work of setting up the try at runtime, the code's metadata is structured at compile time such that when an exception is thrown, it now does a relatively expensive operation of walking up the stack an...
How do I write a for loop in bash
... doSomething($n)
done
Note the $(...) syntax. It's a bash behaviour, it allows you to pass the output from one command (in our case from seq) to another (the for)
This is really useful when you have to iterate over all directories in some path, for example:
for d in $(find $somepath -type d)
do...
Command substitution: backticks or dollar sign / paren enclosed? [duplicate]
...orm. The second form, using a pair of backquotes (the "`" character, also called a backtick and a grave accent), is the historical way of doing it. The first form, using dollar sign and parentheses, is a newer POSIX form, which means it's probably a more standard way of doing it. In turn, I'd think ...
When to wrap quotes around a shell variable?
... quote it if it can either be empty or contain spaces (or any whitespace really) or special characters (wildcards). Not quoting strings with spaces often leads to the shell breaking apart a single argument into many.
$? doesn't need quotes since it's a numeric value. Whether $URL needs it depends o...
mingw-w64 threads: posix vs win32
I'm installing mingw-w64 on Windows and there are two options: win32 threads and posix threads. I know what is the difference between win32 threads and pthreads but I don't understand what is the difference between these two options. I doubt that if I will choose posix threads it will prevent me fro...
What's the difference between NOT EXISTS vs. NOT IN vs. LEFT JOIN WHERE IS NULL?
... NULL is less efficient
In PostgreSQL, NOT IN is less efficient
In Oracle, all three methods are the same.
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Chrome DevTools Devices does not detect device when plugged in
...s://developers.google.com/chrome-developer-tools/docs/remote-debugging
Install Windows USB driver http://developer.samsung.com/android/tools-sdks/Samsung-Android-USB-Driver-for-Windows
Install Android SDK http://developer.android.com/sdk/index.html
Install Android SDK Platform-tools http://developer...