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Design Patterns: Factory vs Factory method vs Abstract Factory
...family of objects that need to be of "the same kind", and have some common base classes. Here's a vaguely fruit-related example. The use case here is that we want to make sure that we don't accidentally use an OrangePicker on an Apple. As long at we get our Fruit and Picker from the same factory, th...
Two single-column indexes vs one two-column index in MySQL?
...nation of giver_id and recipient_id. Mind that index criteria is leftmost based - a query referring to only recipient_id would not be able to use the covering index in the statement I provided.
Additionally, MySQL can only use one index per SELECT so a covering index would be the best means of opt...
What is difference between Errors and Exceptions? [duplicate]
... it. like try something else or write to the log.
try{
//connect to database 1
}
catch(DatabaseConnctionException err){
//connect to database 2
//write the err to log
}
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What is the difference between a pseudo-class and a pseudo-element in CSS?
...description
The pseudo-class concept is introduced to permit selection based on information that lies outside of the document tree or that cannot be expressed using the other simple selectors.
A pseudo-class always consists of a "colon" (:) followed by the name of the pseudo-class and optio...
adding noise to a signal in python
...ance .
When modeling this in python, you can either
1. Calculate variance based on a desired SNR and a set of existing measurements, which would work if you expect your measurements to have fairly consistent amplitude values.
2. Alternatively, you could set noise power to a known level to match som...
How does Zalgo text work?
...th given height. Combining marks may be rendered above, below, or inside a base character
So you can easily construct a character sequence, consisting of a base character and “combining above” marks, of any length, to reach any desired visual height, assuming that the rendering software conform...
Maven project.build.directory
...t;project>
...
<build>
<directory>${project.basedir}/target</directory>
<outputDirectory>${project.build.directory}/classes</outputDirectory>
<finalName>${project.artifactId}-${project.version}</finalName>
<testO...
Short form for Java if statement
... a;
}
else {
max = b;
}
Setting a single variable to one of two states based on a single condition is such a common use of if-else that a shortcut has been devised for it, the conditional operator, ?:. Using the conditional operator you can rewrite the above example in a single line like this:
...
Joda-Time: what's the difference between Period, Interval and Duration?
... at the 1st of the next month but the duration (in milliseconds) will vary based on the month in question
For question 3, A specific method to divide a duration is not really needed because we can always get the number of milliseconds from the duration as a long (using getMillis()), divide it and...
What is the overhead of creating a new HttpClient per call in a WebAPI client?
... you find that you need to use a static HttpClient with different headers, base address, etc. what you will need to do is to create the HttpRequestMessage manually and set those values on the HttpRequestMessage. Then, use the HttpClient:SendAsync(HttpRequestMessage requestMessage, ...)
UPDATE for ....