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Is there a null-coalescing (Elvis) operator or safe navigation operator in javascript?
...e expression is null, but also when it's undefined, false, 0, or the empty string.
– Cameron
Jul 7 '11 at 16:41
...
Check if an array is empty or exists
...ray && !array.length) // array exists, but empty check; if(str) // string not null and not empty. The only gotcha is don't use on numbers if zero is a valid number.
– Rick Love
Feb 27 '17 at 3:47
...
What exactly is an Assembly in C# or .NET?
...quent calls.
The assembly can also contain resources like icons, bitmaps, string tables and so on. Furthermore, the assembly also contains metadata in the assembly manifest - information like version number, strong name, culture, referenced assemblies and so forth.
In 99% of your cases, one assem...
How can I tell when HttpClient has timed out?
...l then throw a TaskCanceledException if it has timed out. Additionally, GetStringAsync and GetStreamAsync internally handle timeout, so they will NEVER throw.
string baseAddress = "http://localhost:8080/";
var client = new HttpClient()
{
BaseAddress = new Uri(baseAddress),
Timeout = Time...
class method generates “TypeError: … got multiple values for keyword argument …”
...ou pass a key word argument for which one of the keys is similar (has same string name) to a positional argument.
>>> class Foo():
... def bar(self, bar, **kwargs):
... print(bar)
...
>>> kwgs = {"bar":"Barred", "jokes":"Another key word argument"}
>>> my...
iphone Core Data Unresolved error while saving
... // If Cocoa generated the error...
if ([[error domain] isEqualToString:@"NSCocoaErrorDomain"]) {
// ...check whether there's an NSDetailedErrors array
NSDictionary *userInfo = [error userInfo];
if ([userInfo valueForKey:@"NSDetailedErrors"] ...
What is the documents directory (NSDocumentDirectory)?
...DomainMask] lastObject];
}
if you need to support iOS 7 or earlier
+ (NSString *) applicationDocumentsDirectory
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *basePath = paths.firstObject;
return basePath;
}
This Do...
How to insert in XSLT
...text disable-output-escaping="yes"> one. The latter is going to produce string literals like &nbsp; for all kinds of output, even for <xsl:output method="text">, and this may happen to be different from what you might wish... On the contrary, getting entities defined for XSLT template v...
Debugging sqlite database on the device
...(preferably a hex-viewer) and check whether it starts with SQLite format 3 string. Also make sure you have a correct sqlite version (i.e. you're not trying to open sqlite3 database with sqlite2 executable). And you may also try other SQLite clients (for example SQLiteStudio). Hope it helps.
...
querySelector search immediate children
...an ID, and if not, they temporarily add an ID, then create a full selector string.
Basically you'd do:
var sel = '> someselector';
var hadId = true;
if( !elem.id ) {
hadID = false;
elem.id = 'some_unique_value';
}
sel = '#' + elem.id + sel;
var result = document.querySelectorAll( sel ...