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How to generate a random int in C?
...
Note: Don't use rand() for security. If you need a cryptographically secure number, see this answer instead.
#include <time.h>
#include <stdlib.h>
srand(time(NULL)); // Initialization, should only be called once.
int r = rand(); // Returns a pseudo-random integer bet...
Objective-C: Where to remove observer for NSNotification?
...his is obviously not a satisfying answer.
I'd recommend, that you add a call [notificationCenter removeObserver: self] in method dealloc of those classes, which you intend to use as observers, as it is the last chance to unregister an observer cleanly. This will, however, only protect you against ...
Entity Framework: table without primary key
...o modify this View.
Fortunately, this View had a column which was a unique string. My solution was to mark this column as a primary key:
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.None)]
[StringLength(255)]
public string UserSID { get; set; }
Cheated EF. Worked perfectly, no one noticed... ...
LINQ with groupby and count
...ready have a list/array of some class that looks like
class UserInfo {
string name;
int metric;
..etc..
}
...
List<UserInfo> data = ..... ;
When you do data.GroupBy(x => x.metric), it means "for each element x in the IEnumerable defined by data, calculate it's .metric, then gr...
django-debug-toolbar not showing up
... to settings.py:
def show_toolbar(request):
return True
SHOW_TOOLBAR_CALLBACK = show_toolbar
That will effectively remove all checks by debug toolbar to determine if it should or should not load itself; it will always just load. Only leave that in for testing purposes, if you forget and launc...
':app:lintVitalRelease' error when generating signed apk
...the errors before disabling them. In my case, they were about some missing strings for specific languages. Hit "Analyze" -> "Inspect code .."
– Markus
May 29 '18 at 14:11
2
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What Vim command(s) can be used to quote/unquote words?
...tes.
Change single quotes to double quotes
va':s/\%V'\%V/"/g
va' - Visually select the quoted word and the quotes.
:s/ - Start a replacement.
\%V'\%V - Only match single quotes that are within the visually selected region.
/"/g - Replace them all with double quotes.
...
Is Redis just a cache?
...e, Redis lets you operate on the values. There are 5 data types in Redis - Strings, Sets, Hash, Lists and Sorted Sets. Each data type exposes various operations.
The best way to understand Redis is to model an application without thinking about how you are going to store it in a database.
Lets sa...
getResourceAsStream returns null
...sStream("MyTest.txt");
byte [] b = new byte[256];
int val = 0;
String txt = null;
do {
try {
val = result.read(b);
if (val > 0) {
txt += new String(b, 0, val);
}
} catch (IOException e) {
e.printStackT...
How to select distinct rows in a datatable and store into an array
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@Lijo, the ToTable(boolean, params string[] columnNames) method allows for multiple columns to be specified.
– Kristen Hammack
Aug 23 '18 at 20:48
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