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How to check a not-defined variable in JavaScript
...ue for things that don't exist, undefined. The DOM returns null for almost all cases where it fails to find some structure in the document, but in JavaScript itself undefined is the value used.
Second, no, there is not a direct equivalent. If you really want to check for specifically for null, do:
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How to detect modifier key states in WPF?
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Much better solution. It also allows you to check all modifiers at once. If you want to handle Ctrl+F, you won't want to handle Ctrl+Shift+F, so you could just check for (e.Key == Key.F && e.KeyboardDevice.Modifiers == ModifierKeys.Control) instea...
CSS I want a div to be on top of everything
...e level of the common parent the first descendants have a defined z-index.
All other descendants can never be in the foreground if at the base there is a lower definite z-index.
In this snippet example, div1-2-1 has a z-index of 1000 but is nevertheless under the div1-1-1 which has a z-index of 3.
T...
How does Activity.finish() work in Android?
Could someone provide a description of what happens when an Activity calls its finish() method?
4 Answers
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Is there a way to loop through a table variable in TSQL without using a cursor?
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First of all you should be absolutely sure you need to iterate through each row — set based operations will perform faster in every case I can think of and will normally use simpler code.
Depending on your data it may be possible t...
Using reCAPTCHA on localhost
...a human verification in one of the sessions. For the development, I'm initially running the system locally and when it is ready, I'm gonna make put it on in a certain domain.
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Is there a predefined enumeration for Month in the .NET library?
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If you are a culturally sensitive, time traveling programmer, be aware that there have been cultures that had a decimal week (eg Revolutionary France) en.wikipedia.org/wiki/Decimal_calendar
– Matthew Lock
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Can Retrofit with OKHttp use cache data when offline
...Just a word of advice: HttpResponseCache has been renamed to Cache.** Install it with OkHttpClient.setCache(...) instead of OkHttpClient.setResponseCache(...).
– Henrique de Sousa
May 28 '15 at 11:46
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How to undo a git merge with conflicts
...nges from before the merge, although it cannot always do so reliably. Generally you shouldn't merge with uncommitted changes anyway.
Prior to version 1.7.4:
git reset --merge
This is older syntax but does the same as the above.
Prior to version 1.6.2:
git reset --hard
which removes all uncom...
How to set working/current directory in Vim?
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@falstro, do you know how :cd command can apply to all windows within the same vim running instances? Ex: when using split :sp
– mgouin
Jan 19 '17 at 21:29
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