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How do I check in JavaScript if a value exists at a certain array index?
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Conceptually, arrays in JavaScript contain array.length elements, starting with array[0] up until array[array.length - 1]. An array element with index i is defined to be part of the array if i is between 0 and array.length - 1 inclusive. If i is not in this range it's not in the array.
S...
C# 3.0 auto-properties — useful or not? [closed]
Note: This was posted when I was starting out C#. With 2014 knowledge, I can truly say that auto-properties are among the best things that ever happened to the C# language.
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Add a prefix to all Flask routes
...lf.app = app
self.prefix = prefix
def __call__(self, environ, start_response):
if environ['PATH_INFO'].startswith(self.prefix):
environ['PATH_INFO'] = environ['PATH_INFO'][len(self.prefix):]
environ['SCRIPT_NAME'] = self.prefix
return self.ap...
Fixing “Lock wait timeout exceeded; try restarting transaction” for a 'stuck" Mysql table?
...ctions with
SELECT * FROM `information_schema`.`innodb_trx` ORDER BY `trx_started`
Your transaction should be one of the first, because it's the oldest in the list. Now just take the value from trx_mysql_thread_id and send it the KILL command:
KILL 1234;
If you're unsure which transaction is y...
Show spinner GIF during an $http request in AngularJS?
...var spinnerFunction = function (data, headersGetter) {
// todo start the spinner here
//alert('start spinner');
$('#mydiv').show();
return data;
};
$httpProvider.defaults.transformRequest.push(spinnerFunction);
})
// register the in...
random.seed(): What does it do?
...pattern of random numbers. This way you are generating them right from the start. You give a different seed- it starts with a different initial (above 3).
Given a seed, it will generate random numbers between 1 and 10 one after another. So you assume one set of numbers for one seed value.
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Why do we use Base64?
...They are used for different purposes.
When you encode text in ASCII, you start with a text string and convert it to a sequence of bytes.
When you encode data in Base64, you start with a sequence of bytes and convert it to a text string.
To understand why Base64 was necessary in the first place ...
I forgot the password I entered during postgres installation
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or Peer autehication should be present.
local all all trust
restart your PostgreSQL server (e.g., on Linux:)
sudo /etc/init.d/postgresql restart
If the service (daemon) doesn't start reporting in log file:
local connections are not supported by this build
you should change
loca...
Do unix timestamps change across timezones?
...of the length of the flight, without having to consider what time zone the starting and ending airports are in. Indeed, I've taken flights that started in daylight savings time and ended after it, or vice versa!
– RobP
Apr 14 '14 at 14:28
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What's the difference between an exclusive lock and a shared lock?
... locked, shared locks cannot be obtained.
Other teachers won't come up and start writing either, or the board becomes unreadable, and confuses students => If an object is exclusively locked, other exclusive locks cannot be obtained.
When the students are reading (shared locks) what is on the bo...