[Python] What does ** (double star/asterisk) and * (star/asterisk) do for parameters?

In the following method definitions, what does the * and ** do for param2?

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The *args and **kwargs is a common idiom to allow arbitrary number of arguments to functions as described in the section more on defining functions in the Python documentation.

The *args will give you all function parameters as a tuple: Continue reading “[Python] What does ** (double star/asterisk) and * (star/asterisk) do for parameters?”

How to return the response from an asynchronous call?

I have a function foo which makes an Ajax request. How can I return the response from foo?

I tried to return the value from the success callback as well as assigning the response to a local variable inside the function and return that one, but none of those ways actually return the response.

Continue reading “How to return the response from an asynchronous call?”

How can I prevent SQL-injection in PHP?

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to SQL injection, like in the following example:

That’s because the user can input something like value'); DROP TABLE table;--, and the query becomes:

INSERT INTO table (column) VALUES(‘value’); DROP TABLE table;–‘)

What can be done to prevent this from happening? Continue reading “How can I prevent SQL-injection in PHP?”

Why is processing a sorted array faster than an unsorted array?

Here is a piece of C++ code that seems very peculiar. For some strange reason, sorting the data miraculously makes the code almost six times faster.

Continue reading “Why is processing a sorted array faster than an unsorted array?”