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How can I check if an element exists in the visible DOM?
How do you test an element for existence without the use of the getElementById method?
25 Answers
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Converting a string to JSON object
...follow
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edited Mar 8 '14 at 16:35
Durandal
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Quickly find whether a value is present in a C array?
I have an embedded application with a time-critical ISR that needs to iterate through an array of size 256 (preferably 1024, but 256 is the minimum) and check if a value matches the arrays contents. A bool will be set to true is this is the case.
...
How to check if a process id (PID) exists
...ess, use
kill -0 $pid
But just as @unwind said, if you're going to kill it anyway, just
kill $pid
or you will have a race condition.
If you want to ignore the text output of kill and do something based on the exit code, you can
if ! kill $pid > /dev/null 2>&1; then
echo "Could ...
What is a practical use for a closure in JavaScript?
...tion();
}
}
})();
As you can see there, a is now an object, with a method publicfunction ( a.publicfunction() ) which calls privatefunction, which only exists inside the closure. You can NOT call privatefunction directly (i.e. a.privatefunction() ), just publicfunction().
Its a minim...
Why are hexadecimal numbers prefixed with 0x?
...
Short story: The 0 tells the parser it's dealing with a constant (and not an identifier/reserved word). Something is still needed to specify the number base: the x is an arbitrary choice.
Long story: In the 60's, the prevalent programming number systems were d...
How do I find the length of an array?
...f(a)/sizeof(*a)) << std::endl;
This doesn't work on pointers (i.e. it won't work for either of the following):
int *p = new int[7];
std::cout << "Length of array = " << (sizeof(p)/sizeof(*p)) << std::endl;
or:
void func(int *p)
{
std::cout << "Length of array ...
How to automatically install Emacs packages by specifying a list of package names?
...ackages you want
(setq package-list '(package1 package2))
; list the repositories containing them
(setq package-archives '(("elpa" . "http://tromey.com/elpa/")
("gnu" . "http://elpa.gnu.org/packages/")
("marmalade" . "http://marmalade-repo.org/packa...
android studio 0.4.2: Gradle project sync failed error
...error when opening a project:
'Gradle project sync failed. Basic functionality (e.g. editing, debugging) will not work proprerly'
...
Warning: “format not a string literal and no format arguments”
...think NSLog() likes taking only one argument, which is what you're passing it. Also, it already does the formatting for you. Why not just do this?
NSLog(@"%@ %@, %@",
errorMsgFormat,
error,
[error userInfo]);
Or, since you say errorMsgFormat is a format string with a sin...