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Whether a variable is undefined [duplicate]
...ease use typeof(var) === 'undefined' as undefined is not a constant in JavaScript.
– JonnyReeves
Feb 12 '12 at 10:21
26
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What is function overloading and overriding in php?
...that method.
In PHP, you can only overload methods using the magic method __call.
An example of overriding:
<?php
class Foo {
function myFoo() {
return "Foo";
}
}
class Bar extends Foo {
function myFoo() {
return "Bar";
}
}
$foo = new Foo;
$bar = new Bar;
echo($foo-&...
Backup/Restore a dockerized PostgreSQL database
...
Backup your databases
docker exec -t your-db-container pg_dumpall -c -U postgres > dump_`date +%d-%m-%Y"_"%H_%M_%S`.sql
Restore your databases
cat your_dump.sql | docker exec -i your-db-container psql -U postgres
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How to validate inputs dynamically created using ng-repeat, ng-show (angular)
... of today, it is not possible (without using a custom directive) to dynamically generate a name of an input. Indeed, checking input docs we can see that the name attribute accepts a string only.
To solve the 'dynamic name' problem you need to create an inner form (see ng-form):
<div ng-repeat="...
How do I make python wait for a pressed key?
I want my script to wait until the user presses any key.
12 Answers
12
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Functional programming - is immutability expensive? [closed]
...’d like to clarify some points.
The “in-place” quicksort isn’t really in-place (and quicksort is not by definition in-place). It requires additional storage in the form of stack space for the recursive step, which is in the order of O(log n) in the best case, but O(n) in the worst case.
Im...
Where to define custom error types in Ruby and/or Rails?
... error types in a Ruby library (gem) or Ruby on Rails application? Specifically:
5 Answers
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Natural Sort Order in C#
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@linquize - He said .NET not Mono, so Linux/OSX isn't really a concern. Windows Phone/Metro didn't exist in 2008 when this answer was posted. And how often do you do file operations in Silverlight? So for the OP, and probably most other people, it was a suitable answer. In any cas...
How to find all serial devices (ttyS, ttyUSB, ..) on Linux without opening them?
What is the proper way to get a list of all available serial ports/devices on a Linux system?
12 Answers
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How to toggle a value in Python
...; toggle()
'blue'
Note that in Python 3 the next() method was changed to __next__(), so the first line would be now written as toggle = itertools.cycle(['red', 'green', 'blue']).__next__
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