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Difference between Static and final?
...he initialization of any instance variables.
A single copy to be shared by all instances of the class.
A static variable can be accessed directly by the class name and doesn’t need any object.
Syntax: Class.variable
Static method
It is a method which belongs to the class and not to the objec...
What's the difference between a 302 and a 307 redirect?
...(RFC 2616):
Note: RFC 1945 and RFC 2068 specify that the client is not allowed to
change the method on the redirected
request. However, most existing user
agent implementations treat 302 as if
it were a 303 response, performing a
GET on the Location field-value
regardless of the ori...
How to find Unused Amazon EC2 Security groups
...AWS CLI tool, I found an easy way to get what I need:
First, get a list of all security groups
aws ec2 describe-security-groups --query 'SecurityGroups[*].GroupId' --output text | tr '\t' '\n'
Then get all security groups tied to an instance, then piped to sort then uniq:
aws ec2 describe-instance...
Default parameter for CancellationToken
...ace methods, the same can be achieved using extension methods:
interface IFoo
{
Task DoAsync(CancellationToken ct);
}
static class Foo
{
public static Task DoAsync(this IFoo foo) => foo.DoAsync(CancellationToken.None);
}
This results in a slimmer interface and spares implementers from...
Common use-cases for pickle in Python
...hon data over a TCP connection in a multi-core or distributed system (marshalling)
3) storing python objects in a database
4) converting an arbitrary python object to a string so that it can be used as a dictionary key (e.g. for caching & memoization).
There are some issues with the last one ...
How to make an image center (vertically & horizontally) inside a bigger div [duplicate]
...
Personally, I'd place it as the background image within the div, the CSS for that being:
#demo {
background: url(bg_apple_little.gif) no-repeat center center;
height: 200px;
width: 200px;
}
(Assumes a div with id="de...
What's the correct way to communicate between controllers in AngularJS?
...ms as raised by @numan. That is because the event will bubble down through all scopes.
However, the latter (using $rootScope.$emit + $rootScope.$on) does not suffer from this and can therefore be used as a fast communication channel!
From the angular documentation of $emit:
Dispatches an even...
Get first key in a (possibly) associative array?
...
2019 Update
Starting from PHP 7.3, there is a new built in function called array_key_first() which will retrieve the first key from the given array without resetting the internal pointer. Check out the documentation for more info.
You can use reset and key:
reset($array);
$first_key = key(...
Can I escape a double quote in a verbatim string literal?
In a verbatim string literal (@"foo") in C#, backslashes aren't treated as escapes, so doing \" to get a double quote doesn't work. Is there any way to get a double quote in a verbatim string literal?
...
Is there any haskell function to concatenate list with separator?
...gonkai Not sure what exactly you're referring to, but yes, these functions all allow arbitrary strings as both the separator and the elements. For example, intercalate "," ["some", "", "string"] = "some,,string" and intercalate "" ["foo", "bar"] = "foobar"
– Niklas B.
...