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Factory pattern in C#: How to ensure an object instance can only be created by a factory class?
...some check before creating an object, probably in its constructor. This is all okay until I decide I want to make this check be a part of the business logic. So, how can I arrange for a business object to be creatable only through some method in my business logic class but never directly? The first ...
What is the printf format specifier for bool?
...sing a single char * to printf() is considered bad practice because it's really supposed to be a format string, and an unescaped percent sign might cause your program to blow up (see here for more). Thus, printf("%s", ...) is safer. If you're not doing any actual formatting to begin with, the printf...
Get last element of Stream/List in a one-liner
...e for the general case:
Stream<T> stream = ...; // sequential or parallel stream
Optional<T> last = stream.reduce((first, second) -> second);
This implementations works for all ordered streams (including streams created from Lists). For unordered streams it is for obvious reasons u...
How do you version your database schema? [closed]
How do you prepare your SQL deltas? do you manually save each schema-changing SQL to a delta folder, or do you have some kind of an automated diffing process?
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Error: Jump to case label
...code, if foo equals 1, everything is ok, but if it equals 2, we'll accidentally use the i variable which does exist but probably contains garbage.
switch(foo) {
case 1:
int i = 42; // i exists all the way to the end of the switch
dostuff(i);
break;
case 2:
dostuff(i*2); // i is ...
‘ld: warning: directory not found for option’
...
Be careful of deleting if you actually need that library path. Verify that the path specified in the error exists. The location of the library on disk may have been moved.
– AWrightIV
Sep 17 '13 at 21:59
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Detect blocked popup in Chrome
...code I use for cross-browser detection, without the Chrome part.
function _hasPopupBlocker(poppedWindow) {
var result = false;
try {
if (typeof poppedWindow == 'undefined') {
// Safari with popup blocker... leaves the popup window handle undefined
result = t...
How does zip(*[iter(s)]*n) work in Python?
... each element is x. *arg unpacks a sequence into arguments for a function call. Therefore you're passing the same iterator 3 times to zip(), and it pulls an item from the iterator each time.
x = iter([1,2,3,4,5,6,7,8,9])
print zip(x, x, x)
...
Best way to read a large file into a byte array in C#?
...
Simply replace the whole thing with:
return File.ReadAllBytes(fileName);
However, if you are concerned about the memory consumption, you should not read the whole file into memory all at once at all. You should do that in chunks.
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Creating a segue programmatically
I have a common UIViewController that all my UIViewsControllers extend to reuse some common operations.
13 Answers
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