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Easiest way to check for an index or a key in an array?
... tests only for existence [of parameter]
This answer is actually adapted from the answers for this SO question: How to tell if a string is not defined in a bash shell script?
A wrapper function:
exists(){
if [ "$2" != in ]; then
echo "Incorrect usage."
echo "Correct usage: exists {k...
How do I make a transparent border with CSS?
...(255,255,255,.5);
}
Demo
Here, you can change the opacity of the border from 0-1
If you simply want a complete transparent border, the best thing to use is transparent, like border: 1px solid transparent;
share
...
What is the purpose of “&&” in a shell command?
...the || which is an OR_IF with similar semantics.
Grammar symbols, quoted from the documentation:
%token AND_IF OR_IF DSEMI
/* '&&' '||' ';;' */
And the Grammar (also quoted from the documentation), which shows that any number of AND_IFs (&&) and/or OR_I...
difference between use and require
...h says "namespaces are a honking great idea, we should have more of them" (from "The Zen of Python") -- so e.g. that style recommends not using "using namespace foo;" in C++, so that readers and maintainers of the code won't have to worry "where does this bar come from" but see a more explicit foo::...
Get image data url in JavaScript?
...
Note: This only works if the image is from the same domain as the page, or has the crossOrigin="anonymous" attribute and the server supports CORS. It's also not going to give you the original file, but a re-encoded version. If you need the result to be identical ...
When should Flask.g be used?
I saw that g will move from the request context to the app context in Flask 0.10, which made me confused about the intended use of g .
...
Show all Elasticsearch aggregation results/buckets and not just 10
... @batmaci it was deprecated in 2.x so would still work and was removed from 5.x
– keety
Apr 21 '17 at 15:32
...
List changes unexpectedly after assignment. How do I clone or copy it to prevent this?
...
(Here's the script if anyone's interested or wants to raise any issues:)
from copy import deepcopy
class old_class:
def __init__(self):
self.blah = 'blah'
class new_class(object):
def __init__(self):
self.blah = 'blah'
dignore = {str: None, unicode: None, int: None, type...
How to use System.Net.HttpClient to post a complex type?
... HttpRequestMessage<Widget>(widget)
will no longer work.
Instead, from this post, the ASP.NET team has included some new calls to support this functionality:
HttpClient.PostAsJsonAsync<T>(T value) sends “application/json”
HttpClient.PostAsXmlAsync<T>(T value) sends “appli...
What are the differences between WCF and ASMX web services?
...asy and simple to write and configure
only available in IIS
only callable from HTTP
WCF can be:
hosted in IIS, a Windows Service, a Winforms application, a console app - you have total freedom
used with HTTP (REST and SOAP), TCP/IP, MSMQ and many more protocols
In short: WCF is here to replac...