大约有 43,000 项符合查询结果（耗时：0.0671秒） [XML]
Can a class member function template be virtual?
I have heard that C++ class member function templates can't be virtual. Is this true?
12 Answers
...
Insert results of a stored procedure into a temporary table
How do I do a SELECT * INTO [temp table] FROM [stored procedure] ? Not FROM [Table] and without defining [temp table] ?
...
How can I select an element with multiple classes in jQuery?
I want to select all the elements that have the two classes a and b .
13 Answers
13...
Drop unused factor levels in a subsetted data frame
I have a data frame containing a factor . When I create a subset of this dataframe using subset or another indexing function, a new data frame is created. However, the factor variable retains all of its original levels, even when/if they do not exist in the new dataframe.
...
What is the purpose of mock objects?
I am new to unit testing, and I continously hear the words 'mock objects' thrown around a lot. In layman's terms, can someone explain what mock objects are, and what they are typically used for when writing unit tests?
...
What is the difference between Python's list methods append and extend?
What's the difference between the list methods append() and extend() ?
20 Answers
2...
What is meant by the term “hook” in programming?
I recently heard the term "hook" while talking to some people about a program I was writing. I'm unsure exactly what this term implies although I inferred from the conversation that a hook is a type of function. I searched for a definition but was unable to find a good answer. Would someone be ab...
Algorithm to generate all possible permutations of a list?
Say I have a list of n elements, I know there are n! possible ways to order these elements. What is an algorithm to generate all possible orderings of this list? Example, I have list [a, b, c]. The algorithm would return [[a, b, c], [a, c, b,], [b, a, c], [b, c, a], [c, a, b], [c, b, a]].
...
Is JavaScript a pass-by-reference or pass-by-value language?
The primitive types (number, string, etc.) are passed by value, but objects are unknown, because they can be both passed-by-value (in case we consider that a variable holding an object is in fact a reference to the object) and passed-by-reference (when we consider that the variable to the object hol...
Downcasting in Java
Upcasting is allowed in Java, however downcasting gives a compile error.
11 Answers
1...