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Direct casting vs 'as' operator?
... tend to almost never use 2 since if something is not the right type, I usually expect an exception to occur. I have only seen a need for this return-null type of functionality with badly designed libraries which use error codes (e.g. return null = error, instead of using exceptions).
3 is not a ca...
NSDictionary - Need to check whether dictionary contains key-value pair or not
...uldn't we mistakenly think that the key isn't present in the dictionary at all?
– jbx72487
Feb 1 '13 at 18:51
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NSUserDefaults - How to tell if a key exists
I'm working on a small iPhone app, and I am using NSUserDefaults as my data persistence. It only has to keep track of a few things, such as some names and some numbers so I figure I might as well keep it simple.
...
How to resize a VirtualBox vmdk file
... iso from within the virtualbox settings).
P.S. If your new size is too small, you'll get the same error even with your new vdi file.
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Is it possible to delete an object's property in PHP?
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unset($a->new_property);
This works for array elements, variables, and object attributes.
Example:
$a = new stdClass();
$a->new_property = 'foo';
var_export($a); // -> stdClass::__set_state(array('new_property' => 'foo'))
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关于App Inventor 2过程积木，被问最多的6个问题 - App应用开发 - 清泛IT社...
...>做过程名。完整列表在 <a href="https://en.wikipedia.org/wiki/List_of_Java_keywords" target="_blank">Java关键字列表</a> ，常见的有 <font face="Courier New">if</font>、<font face="Courier New">else</font>、<font face="Courier New">while</font>、<font face="Courier New">for</font...
python pandas dataframe to dictionary
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See the docs for to_dict. You can use it like this:
df.set_index('id').to_dict()
And if you have only one column, to avoid the column name is also a level in the dict (actually, in this case you use the Series.to_dict()):
df.set_index('id')...
PostgreSQL query to list all table names?
Is there any query available to list all tables in my Postgres DB.
7 Answers
7
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How to change Vagrant 'default' machine name?
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I found the multiple options confusing, so I decided to test all of them to see exactly what they do.
I'm using VirtualBox 4.2.16-r86992 and Vagrant 1.3.3.
I created a directory called nametest and ran
vagrant init precise64 http://files.vagrantup.com/precise64.box
to generate a...
How do I use WebRequest to access an SSL encrypted site using https?
...ValidationCallback <- Security.RemoteCertificateValidationCallback (fun _ _ _ _ -> true)
– David Grenier
Jan 10 '12 at 21:25
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