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Dynamically creating keys in a JavaScript associative array
... that, obviously an array is needed).
A quick Google search brings up hash tables in JavaScript.
Example code for looping over values in a hash (from the aforementioned link):
var myArray = new Array();
myArray['one'] = 1;
myArray['two'] = 2;
myArray['three'] = 3;
// Show the values stored
for (var...
Inheritance and Overriding __init__ in python
...
The book is a bit dated with respect to subclass-superclass calling. It's also a little dated with respect to subclassing built-in classes.
It looks like this nowadays:
class FileInfo(dict):
"""store file metadata"""
def __init__(self, filename=None):
super(FileInfo,...
How to find the size of localStorage
...ly developing a site that will make use of HTML5's localStorage. I've read all about the size limitations for different browsers. However, I haven't seen anything on how to find out the current size of a localStorage instance. This question seems to indicate that JavaScript doesn't have a built in...
Define a lambda expression that raises an Exception
...ur goal is to avoid a def, this obviously doesn't cut it. It does, however allow you to conditionally raise exceptions, e.g.:
y = lambda x: 2*x if x < 10 else raise_(Exception('foobar'))
Alternatively you can raise an exception without defining a named function. All you need is a strong stom...
Is it ever advantageous to use 'goto' in a language that supports loops and functions? If so, why?
...o this already):
Cleanly exiting a function
Often in a function, you may allocate resources and need to exit in multiple places. Programmers can simplify their code by putting the resource cleanup code at the end of the function, and all "exit points" of the function would goto the cleanup label....
What does the “yield” keyword do?
... list, you can read its items one by one. Reading its items one by one is called iteration:
>>> mylist = [1, 2, 3]
>>> for i in mylist:
... print(i)
1
2
3
mylist is an iterable. When you use a list comprehension, you create a list, and so an iterable:
>>> mylist = [...
How to drop a PostgreSQL database if there are active connections to it?
...ns after they've finished with their current transaction and then drop the table(s) in question?
– paulkon
Apr 25 '15 at 17:07
5
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What do REFRESH and MERGE mean in terms of databases?
...adable):
MERGE - for existing objects, to merge the existing data in the table with the data in my object. (sync to database)
PERSIST - is create new records from object in the database.
REFRESH - is to refresh the data in the object. Perhaps there was a change on the database which needs to be sy...
How do I modify the URL without reloading the page?
...modify the URL in the address bar client-side. For instance, if you have a table of data with paging, sorting and filtering, and want those things to be Ajax powered, but still update the URL so that the current state of the page is bookmarkable. I can understand the security risks with modifying t...
django models selecting single field
I have a table/models called Employees and I would like to get all rows of a single field as a queryset.
5 Answers
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