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What is the definition of “interface” in object oriented programming
... one of the more overloaded and confusing terms in development.
It is actually a concept of abstraction and encapsulation. For a given "box", it declares the "inputs" and "outputs" of that box. In the world of software, that usually means the operations that can be invoked on the box (along with ar...
Django rest framework nested self-referential objects
... the `subcategories` field
return CategorySerializer()
Actually, as you've noted the above isn't quite right.
This is a bit of a hack, but you might try adding the field in after the serializer is already declared.
class CategorySerializer(serializers.ModelSerializer):
parentCat...
How to get an object's properties in JavaScript / jQuery?
...Script's native for in loop:
var obj = {
foo: 'bar',
base: 'ball'
};
for(var key in obj) {
alert('key: ' + key + '\n' + 'value: ' + obj[key]);
}
or using jQuery's .each() method:
$.each(obj, function(key, element) {
alert('key: ' + key + '\n' + 'value: ' + element);
});
W...
Proper use of beginBackgroundTaskWithExpirationHandler
...l need to wrap it in a background task. It's also very important that you call endBackgroundTask when you're finished - otherwise the app will be killed after its allotted time has expired.
Mine tend look something like this:
- (void) doUpdate
{
dispatch_async(dispatch_get_global_queue(DISPAT...
Get value from SimpleXMLElement Object
... i can't believe this is so complicated. why would they make a class called "getName" but not "getValue"? why would they print empty string if you printed it instead of converted it manually to (string). WHY??
– user151496
Oct 17 '16 at 12:31
...
What is your preferred style for naming variables in R? [closed]
...
Good previous answers so just a little to add here:
underscores are really annoying for ESS users; given that ESS is pretty widely used you won't see many underscores in code authored by ESS users (and that set includes a bunch of R Core as well as CRAN authors, excptions like Hadley notwithsta...
jQuery Ajax File Upload
...ed. E.g. through FormData object, but unfortunately it is not supported by all/old browsers.
FormData support starts from following desktop browsers versions.
IE 10+
Firefox 4.0+
Chrome 7+
Safari 5+
Opera 12+
For more detail, see MDN link.
...
Create a pointer to two-dimensional array
...d T[10] are different types.
The following alternative doesn't work at all, because the element type of the array, when you view it as a one-dimensional array, is not uint8_t, but uint8_t[20]
uint8_t *matrix_ptr = l_matrix; // fail
The following is a good alternative
uint8_t (*matrix_ptr)[...
Is there a way to pass optional parameters to a function?
Is there a way in Python to pass optional parameters to a function while calling it and in the function definition have some code based on "only if the optional parameter is passed"
...
Read file from line 2 or skip header row
... This is fine UNTIL the file is too large to read. This is fine for small files.
– CppLearner
Feb 5 '18 at 2:05
1
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