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How to test if list element exists?
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This is actually a bit trickier than you'd think. Since a list can actually (with some effort) contain NULL elements, it might not be enough to check is.null(foo$a). A more stringent test might be to check that the name is actually defined in the list:
foo <- list(a...
Linq to Entities - SQL “IN” clause
In T-SQL you could have a query like:
8 Answers
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Undoing a git rebase
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The easiest way would be to find the head commit of the branch as it was immediately before the rebase started in the reflog...
git reflog
and to reset the current branch to it (with the usual caveats about being absolutely sure before reseting with t...
Co-variant array conversion from x to y may cause run-time exception
I have a private readonly list of LinkLabel s ( IList<LinkLabel> ). I later add LinkLabel s to this list and add those labels to a FlowLayoutPanel like follows:
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Event listener for when element becomes visible?
I am building a toolbar that is going to be included into a page. the div it is going to be included in will default to display:none . Is there a way i can put an event listener on my toolbar to listen for when it becomes visible so it can initialize? or will I have to pass it a variable from the c...
Open another application from your own (intent)
I know how to update my own programs, and I know how to open programs using the a predefined Uri (for sms or email for example)
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Reason to Pass a Pointer by Reference in C++?
Under which circumstances would you want to use code of this nature in c++?
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D3.js: what is 'g' in .append(“g”) D3.js code?
I am new to D3.js , started learning today only
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How do I change tab size in Vim?
Every time I add a selector in CSS and I press Enter to define the properties it ends up like this:
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Unix tail equivalent command in Windows Powershell
I have to look at the last few lines of a large file (typical size is 500MB-2GB). I am looking for a equivalent of Unix command tail for Windows Powershell. A few alternatives available on are,
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