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What is the purpose of .PHONY in a Makefile?
...meaning: a) its behavior will not be altered if the file does exist and b) extra stat() will not be called.
Generally all targets in your Makefile which do not produce an output file with the same name as the target name should be PHONY. This typically includes all, install, clean, distclean, and s...
How can I append a string to an existing field in MySQL?
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You need to use the CONCAT() function in MySQL for string concatenation:
UPDATE categories SET code = CONCAT(code, '_standard') WHERE id = 1;
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Using generic std::function objects with member functions in one class
...tip: member function pointer can be implicitly cast to std::function, with extra this as it's first parameter, like std::function<void(Foo*, int, int)> = &Foo::doSomethingArgs
– landerlyoung
Nov 25 '19 at 6:44
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Why does one often see “null != variable” instead of “variable != null” in C#?
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In earlier times, people would forget the '!' (or the extra '=' for equality, which is more difficult to spot) and do an assignment instead of a comparison. putting the null in front eliminates the possibility for the bug, since null is not an l-value (I.E. it can't be assigned ...
How can I access and process nested objects, arrays or JSON?
...a key -> value structure. Keys in an array must be numeric, whereas any string can be used as key in objects. The key-value pairs are also called the "properties".
Properties can be accessed either using dot notation
const value = obj.someProperty;
or bracket notation, if the property name wo...
How can I put a ListView into a ScrollView without it collapsing?
... in charge of ListView for the past 2 or 3 years :) ListView does a lot of extra work to optimize the use of adapters. Trying to work around it will still cause ListView to do a lot of work a LinearLayout wouldn't have to do. I won't go into the details because there's not enough room here to explai...
How do I get the value of text input field using JavaScript?
...s far as I can see, it just doesn't support CSS3 selectors in the selector string.
– Fabrício Matté
Jun 22 '13 at 4:02
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How to use if - else structure in a batch file?
...taneously. In this case you can still use IF...ELSE IF construct, but with extra parentheses to avoid uncertainty for the next ELSE condition:
IF %F%==1 (IF %C%==1 (
::copying the file c to d
copy "%sourceFile1%" "%destinationFile1%" )
) ELSE IF %F%==1 (IF %C%==0 (
::moving the file e t...
Send inline image in email
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Try this
string htmlBody = "<html><body><h1>Picture</h1><br><img src=\"cid:filename\"></body></html>";
AlternateView avHtml = AlternateView.CreateAlternateViewFromString
(htmlBody, ...
Iterate an iterator by chunks (of n) in Python? [duplicate]
...ry and take much longer to run. Why do that if you don't have to? At 200K, extra temp storage makes the overall program take 3.5x longer to run than with it removed. Just that one change. So it is a pretty big deal. NumPy won't work because the iterator is a database cursor, not a list of numbers.
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