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Checking if a string is empty or null in Java [duplicate]
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Correct way to check for null or empty or string containing only spaces is like this:
if(str != null && !str.trim().isEmpty()) { /* do your stuffs here */ }
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Finding Variable Type in JavaScript
..."foo")
"object"
> typeof new Number(42)
"object"
The type of an array is still object. Here you really need the instanceof operator.
Update:
Another interesting way is to examine the output of Object.prototype.toString:
> Object.prototype.toString.call([1,2,3])
"[object Array]"
> Objec...
Public Fields versus Automatic Properties
...You can't databind against a variable.
Changing a variable to a property is a breaking change. For example:
TryGetTitle(out book.Title); // requires a variable
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Why should the “PIMPL” idiom be used? [duplicate]
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edited Sep 12 '13 at 9:49
Oleksiy
28.1k1919 gold b...
Undo git pull, how to bring repos to old state
Is there any way to revert or undo git pull so that my source/repos will come to old state that was before doing git pull ?
I want to do this because it merged some files which I didn't want to do so, but only merge other remaining files. So, I want to get those files back, is that possible?
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What's the difference between VARCHAR and CHAR?
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VARCHAR is variable-length.
CHAR is fixed length.
If your content is a fixed size, you'll get better performance with CHAR.
See the MySQL page on CHAR and VARCHAR Types for a detailed explanation (be sure to also read the comments...
In C#, what happens when you call an extension method on a null object?
...al calls (i.e. it uses the "call" il instruction, not "callvirt") so there is no null check unless you write it yourself in the extension method. This is actually useful in a few cases:
public static bool IsNullOrEmpty(this string value)
{
return string.IsNullOrEmpty(value);
}
public static voi...
Fastest way to tell if two files have the same contents in Unix/Linux?
...ich I need to check whether two files contain the same data or not. I do this a for a lot of files, and in my script the diff command seems to be the performance bottleneck.
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How can I see normal print output created during pytest run?
...ome print statements in my code, and see what gets printed out when I exercise it. My usual way to "exercise" it is with existing pytest tests. But when I run these, I don't seem able to see any standard output (at least from within PyCharm, my IDE).
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LINQ equivalent of foreach for IEnumerable
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There is no ForEach extension for IEnumerable; only for List<T>. So you could do
items.ToList().ForEach(i => i.DoStuff());
Alternatively, write your own ForEach extension method:
public static void ForEach<T>(thi...