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When would you use a WeakHashMap or a WeakReference?
...th user-supplied images, like the
web site design tool I work on.
Naturally you want to cache these
images, because loading them from disk
is very expensive and you want to
avoid the possibility of having two
copies of the (potentially gigantic)
image in memory at once.
Because an...
Parse string to date with moment.js
...utes and just does it's thing if you let it. This was perfect for me as my API call brings back the date and time but I only care about the date.
function momentTest() {
var varDate = "2018-01-19 18:05:01.423";
var myDate = moment(varDate,"YYYY-MM-DD").format("DD-MM-YYYY");
var todayDate = ...
Declaring an enum within a class
...uct Color
{
enum Type
{
Red, Green, Black
};
Type t_;
Color(Type t) : t_(t) {}
operator Type () const {return t_;}
private:
//prevent automatic conversion for any other built-in types such as bool, int, etc
template<typename T>
operator T () const;
};
...
How to count the number of files in a directory using Python
...
For all kind of files, subdirectories included:
import os
list = os.listdir(dir) # dir is your directory path
number_files = len(list)
print number_files
Only files (avoiding subdirectories):
import os
onlyfiles = next(os.w...
Safely casting long to int in Java
...
Yes, it's safe to use existing api as my case, the library already in the project: to throw exception if invalid: Ints.checkedCast(long) and Ints.saturatedCast(long) to get the nearest for converting long to int.
– Osify
...
Convert generic List/Enumerable to DataTable?
...ata)) {
table.Load(reader);
}
This uses FastMember's meta-programming API for maximum performance. If you want to restrict it to particular members (or enforce the order), then you can do that too:
IEnumerable<SomeType> data = ...
DataTable table = new DataTable();
using(var reader = Obje...
Distinct not working with LINQ to Objects
...
LINQ Distinct is not that smart when it comes to custom objects.
All it does is look at your list and see that it has two different objects (it doesn't care that they have the same values for the member fields).
One workaround is to implement the IEquatable interface as shown here.
If yo...
Difference between attr_accessor and attr_accessible
...d that makes a getter and a setter. attr_accessible is a Rails method that allows you to pass in values to a mass assignment: new(attrs) or update_attributes(attrs).
Here's a mass assignment:
Order.new({ :type => 'Corn', :quantity => 6 })
You can imagine that the order might also have a d...
How do you use variables in a simple PostgreSQL script?
...
This doesn't answer the question at all. In MS SQL you can define a var in a query and use it right there, in the same tool. I don't get why people keep proposing this as an answer, in every version of this question.
– stone
...
Replace console output in Python
...his is something I am using:
def startProgress(title):
global progress_x
sys.stdout.write(title + ": [" + "-"*40 + "]" + chr(8)*41)
sys.stdout.flush()
progress_x = 0
def progress(x):
global progress_x
x = int(x * 40 // 100)
sys.stdout.write("#" * (x - progress_x))
s...