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Test whether a glob has any matches in bash
...compgen -G "<glob-pattern>"
Escape the pattern or it'll get pre-expanded into matches.
Exit status is:
1 for no-match,
0 for 'one or more matches'
stdout is a list of files matching the glob.
I think this is the best option in terms of conciseness and minimizing potential side effect...
Python: reload component Y imported with 'from X import Y'?
...nce I have imported a module X in an interpreter session using import X , and the module changes on the outside, I can reload the module with reload(X) . The changes then become available in my interpreter session.
...
In javascript, is an empty string always false as a boolean?
...
Yes. Javascript is a dialect of ECMAScript, and ECMAScript language specification clearly defines this behavior:
ToBoolean
The result is false if the argument is the empty String (its length is zero);
otherwise the result is true
Quote taken from http://www.ecma-inte...
Are arrays in PHP copied as value or as reference to new variables, and when passed to functions?
...e
copying. Use the reference operator to
copy an array by reference.
And the given example :
<?php
$arr1 = array(2, 3);
$arr2 = $arr1;
$arr2[] = 4; // $arr2 is changed,
// $arr1 is still array(2, 3)
$arr3 = &$arr1;
$arr3[] = 4; // now $arr1 and $arr3 are the same
?>
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“Could not find any information for class named ViewController”
...roject.
Steps:
In the project file explorer (left panel) find the class and right click -> Delete
Remove reference (do not move to trash as you will lose the class for good)
Right click on the folder that contained the class -> Add files to ...
Find the class you just deleted in the file sy...
How to obtain the start time and end time of a day?
How to obtain the start time and end time of a day?
14 Answers
14
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How to complete a git clone for a big project on an unstable connection?
...codebase, but at the moment I have an internet connection of about 300kbps and it's just anything but stable. I can get the connection back any moment, but then the git clone process already stopped working, and no way to get it running again. Is there some way to have a more failure-resistant git c...
How to make my custom type to work with “range-based for loops”?
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The standard has been changed since the question (and most answers) were posted in the resolution of this defect report.
The way to make a for(:) loop work on your type X is now one of two ways:
Create member X::begin() and X::end...
Global and local variables in R
I am a newbie for R, and I am quite confused with the usage of local and global variables in R.
3 Answers
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Python != operation vs “is not”
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== is an equality test. It checks whether the right hand side and the left hand side are equal objects (according to their __eq__ or __cmp__ methods.)
is is an identity test. It checks whether the right hand side and the left hand side are the very same object. No methodcalls ...