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What reason is there to use null instead of undefined in JavaScript?
...nce to "nothing". If you are calling a not existing property of an object, then you will get undefined. If I would make that property intentionally empty, then it must be null so you know that it's on purpose. Many javascript libraries work like this way.
– com2ghz
...
INSERT IF NOT EXISTS ELSE UPDATE?
... ID column: In the replacement case the statement would set it to NULL and then a fresh ID would be allocated.
This approach can also be used if you want to leave particular field values alone if the row in the replacement case but set the field to NULL in the insert case.
For example, assuming yo...
How can I safely encode a string in Java to use as a filename?
...rom an external process. I want to use that String to make a filename, and then write to that file. Here's my code snippet to do this:
...
How can I handle time zones in my webapp?
...o save the timezone the device was set to when your app was first run, and then see if it ever changes. If it does change, then the user is probably a traveller and would probably benefit from having the timezone dropdown. Otherwise, just don't show the dropdown and default to the device timezone (b...
Python AttributeError: 'module' object has no attribute 'Serial' [duplicate]
... This looks utterly wrong, sorry. At first the class is Serial not serial, then you don't have to import a class to use it. module.class() should work very fine. Last but not least there is no real explanation for what's going on here at all.
– erikbwork
Apr 16...
Modify table: How to change 'Allow Nulls' attribute from not null to allow null
...
Note if needing to change multiple columns to allow null, then you will need to perform separate ALTER TABLE .. ALTER COLUMN .. commands
– sonyisda1
Feb 17 '17 at 15:14
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Mockito How to mock and assert a thrown exception?
I'm using mockito in a junit test. How do you make an exception happen and then assert that it has (generic pseudo-code)
11...
Can I extend a class using more than 1 class in PHP?
... Can you explain why it is right to first inherit Nurse into Matron, then declare inheritance of HumanEntity into Nurse?
– Qwerty
Feb 26 '14 at 18:01
7
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How to use arguments from previous command?
... and press a number. You can do Alt--to begin specifying a negative number then release Alt and press the digit (this will count from the end of the list of arguments.
Example:
Enter the following command
$ echo a b c d e f g
a b c d e f g
Now at the next prompt, type echo (with a following spa...
Testing modules in rspec
...e. after new has been called. If you were doing this before new is called then you are right you would use include
– Hedgehog
Nov 26 '12 at 10:34
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