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System.currentTimeMillis() vs. new Date() vs. Calendar.getInstance().getTime()
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System.currentTimeMillis() is obviously the most efficient since it does not even create an object, but new Date() is really just a thin wrapper about a long, so it is not far behind. Calendar, on the other hand, is relatively slow and very complex, since it has to deal with the considerab...
Transposing a 2D-array in JavaScript
...lback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.
callback is invoked with three arguments: the value of the element, the index of the element, and the Array object being tra...
How do you create a dropdownlist from an enum in ASP.NET MVC?
...e the Html.DropDownList extension method but can't figure out how to use it with an enumeration.
36 Answers
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Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array
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You could sort the array and then run through it and then see if the next (or previous) index is the same as the current. Assuming your sort algorithm is good, this should be less than O(n2):
const findDuplicates = (arr) => {
let sorted_arr = arr.slice().sort(...
How to wait until an element exists?
...to find out when an element comes into existence? Using plain javascript, with an interval that checks until an element exists, or does jQuery have some easy way to do this?
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How can I prevent the scrollbar overlaying content in IE10?
In IE10, the scrollbar is not always there... and when it appears it comes on as an overlay... It's a cool feature but I would like to turn it off for my specific website as it is a full screen application and my logos and menus are lost behind it.
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How to make a vertical line in HTML
...the markup where you want the line to appear to next, and use CSS to style it:
.verticalLine {
border-left: thick solid #ff0000;
}
<div class="verticalLine">
some other content
</div>
share
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git reset --hard HEAD leaves untracked files behind
When I run git reset --hard HEAD , it's supposed to reset to a pristine version of what you pulled, as I understand it. Unfortunately, it leaves files lying around, as a git status shows a big list of untracked files.
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How to check if a string contains a substring in Bash
...ts:
string='My long string'
if [[ $string == *"My long"* ]]; then
echo "It's there!"
fi
Note that spaces in the needle string need to be placed between double quotes, and the * wildcards should be outside. Also note that a simple comparison operator is used (i.e. ==), not the regex operator =~....
git visual diff between branches
...is great for seeing a visual diff between two files that are checked into git:
How do I view 'git diff' output with a visual diff program?
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