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Can an int be null in Java?
...areful when unboxing null Integers since this can cause a lot of confusion and head scratching!
e.g. this:
int a = object.getA(); // getA returns a null Integer
will give you a NullPointerException, despite object not being null!
To follow up on your question, if you want to indicate the absen...
How do I escape a reserved word in Oracle?
... it graciously allows omitting the double-quotes, in which case it quietly converts the identifier to uppercase:
SELECT MyColumn AS MyColAlias
FROM MyTable Alias
WHERE ThisCol = 'That Value';
gets internally converted to something like:
SELECT "ALIAS" . "MYCOLUMN" AS "MYCOLALIAS"
FROM "THEUSER" ...
How to dynamically build a JSON object with Python?
...and I'm intentionally using this to demonstrate how you can store null and convert it to json null)
import json
print('serialization')
myDictObj = { "name":"John", "age":30, "car":None }
##convert object to json
serialized= json.dumps(myDictObj, sort_keys=True, indent=3)
print(serialized)
## now we...
ViewParam vs @ManagedProperty(value = “#{param.id}”)
... could use <f:viewAction> for that instead.
Allows for nested <f:converter> and <f:validator> for more fine-grained conversion/validation. Even a <h:message> can be attached.
Can be included as GET query string using includeViewParams attribute of <h:link> or includeV...
Priority queue in .Net [closed]
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I like using the OrderedBag and OrderedSet classes in PowerCollections as priority queues.
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Why does the C preprocessor interpret the word “linux” as the constant “1”?
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In the Old Days (pre-ANSI), predefining symbols such as unix and vax was a way to allow code to detect at compile time what system it was being compiled for. There was no official language standard back then (beyond the reference material at the back of the first edition of K&R), a...
How do I get bit-by-bit data from an integer value in C?
...( 1 << k )) >> k
Here we create a mask, apply the mask to n, and then right shift the masked value to get just the bit we want. We could write it out more fully as:
int mask = 1 << k;
int masked_n = n & mask;
int thebit = masked_n >> k;
You can read more...
Python serialization - Why pickle?
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Pickling is a way to convert a python object (list, dict, etc.) into a character stream. The idea is that this character stream contains all the information necessary to reconstruct the object in another python script.
As for where the pickled i...
GridCtrl 控件FAQ - C/C++ - 清泛网 - 专注C/C++及内核技术
...drop highlighted
GVIS_READONLY // Cell is read-only and cannot be edited
GVIS_FIXED // Cell is fixed
GVIS_FIXEDROW // Cell is part of a fixed row
GVIS_FIXEDCOL // Cell is part of a fixed column
...
How can I calculate the time between 2 Dates in typescript
...culate the difference you have to put the + operator,
that way typescript converts the dates to numbers.
+new Date()- +new Date("2013-02-20T12:01:04.753Z")
From there you can make a formula to convert the difference to minutes or hours.
...