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How do I delete an exported environment variable?
... @RodrigoGurgel using echo won't show existing variable set to empty string or nul. to your point, though, a proper way to test for variable would be env | grep -e '^VARNAME='.
– Thomas
Feb 1 '19 at 14:22
...
In what cases do I use malloc and/or new?
... Always use new.
If you need a big chunk of data just do something like:
char *pBuffer = new char[1024];
Be careful though this is not correct:
//This is incorrect - may delete only one element, may corrupt the heap, or worse...
delete pBuffer;
Instead you should do this when deleting an arra...
How to convert java.util.Date to java.sql.Date?
... database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes. Hibernate 5 & JPA 2.2 support java.time.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bun...
How do I directly modify a Google Chrome Extension File? (.CRX)
...w.
2.) The sub folder containing the extension is a random alpha-numeric string named after the extension's ID, which can be found on Chrome's extension page if Developer flag is set to true. (Upper right hand checkbox on the extensions page)
...
How do I edit an existing tag message in git?
...
> }' | # extract all the dates from the info
> tail -2 | head -1)" `# get the second to last date, as the last one is the commit date` \
> git tag tag1 tag1^{} -a -f ...
Difference between is and as keyword
... if an object can be cast to a specific type.
Example:
if (someObject is StringBuilder) ...
as
The as operator attempts to cast an object to a specific type, and returns null if it fails.
Example:
StringBuilder b = someObject as StringBuilder;
if (b != null) ...
Also related:
Casting
...
Flatten an Array of Arrays in Swift
...hmiBozdag's answer,
1. Methods in public extensions are public.
2. Removed extra method, as start index will be always zero.
3. I did not find a way to put compactMap inside for nil and optionals because inside method T is always [Any?], any suggestions are welcomed.
let array = [[[1, 2, 3], 4], 5...
Android - Launcher Icon Size
...ractices/screens_support.html. Search on the page for, "180x180 (3.0x) for extra-extra-high-density". However, I've seen 144 a few places.
– 1.21 gigawatts
Jan 25 '15 at 5:13
...
How to avoid “if” chains?
...e desire to break out of "part of a function" usually means you do need an extra function.
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C# Events and Thread Safety
...ith every event - aka boilerplate code!
public event Action<thisClass, string> Some;
protected virtual void DoSomeEvent(string someValue)
{
var e = Some; // avoid race condition here!
if(null != e) // avoid null condition here!
e(this, someValue);
}
2 - the race condition issue) ...