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Detecting an “invalid date” Date instance in JavaScript
...
Here's how I would do it:
if (Object.prototype.toString.call(d) === "[object Date]") {
// it is a date
if (isNaN(d.getTime())) { // d.valueOf() could also work
// date is not valid
} else {
// date is valid
}
} else {
// not a date
}
Update [2018-05-31]: If yo...
What are the basic rules and idioms for operator overloading?
... itself succeeded, but the result is not what would be expected.
Function call operator
The function call operator, used to create function objects, also known as functors, must be defined as a member function, so it always has the implicit this argument of member functions. Other than this, it ca...
Is it possible to capture a Ctrl+C signal and run a cleanup function, in a “defer” fashion?
...outine to get processor time to handle the signal, the main goroutine must call a blocking operation or call runtime.Gosched in an appropriate place (in your program's main loop, if it has one)
– misterbee
Aug 4 '13 at 15:53
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Using DISTINCT and COUNT together in a MySQL Query
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use
SELECT COUNT(DISTINCT productId) from table_name WHERE keyword='$keyword'
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What is the purpose of wrapping whole Javascript files in anonymous functions like “(function(){ … }
...ction() {
function innerFunction() {
// code
}
}
Now you can call outerFunction(), but the visiblity of innerFunction() is limited to the scope of outerFunction(), meaning it is private to outerFunction(). It basically follows the same principle as variables in Javascript:
var globalV...
How do I execute a program from Python? os.system fails due to spaces in path
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subprocess.call will avoid problems with having to deal with quoting conventions of various shells. It accepts a list, rather than a string, so arguments are more easily delimited. i.e.
import subprocess
subprocess.call(['C:\\Temp\\a b...
What is a callback?
What's a callback and how is it implemented in C#?
11 Answers
11
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Difference between require, include, require_once and include_once?
...on that you do not want to happen twice due to the HTTP overhead
But basically, it's up to you when to use which.
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How to deal with a slow SecureRandom generator?
If you want a cryptographically strong random numbers in Java, you use SecureRandom . Unfortunately, SecureRandom can be very slow. If it uses /dev/random on Linux, it can block waiting for sufficient entropy to build up. How do you avoid the performance penalty?
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IOS: create a UIImage or UIImageView with rounded corners
...iew with rounded corners? Because I want take an UIImage and show it inside an UIImageView , but I don't know how to do it.
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