大约有 43,000 项符合查询结果（耗时：0.0671秒） [XML]
One line if statement not working
I was thinking of something like this?
8 Answers
8
...
Why is creating a new process more expensive on Windows than Linux?
I've heard that creating a new process on a Windows box is more expensive than on Linux. Is this true? Can somebody explain the technical reasons for why it's more expensive and provide any historical reasons for the design decisions behind those reasons?
...
select * vs select column
If I just need 2/3 columns and I query SELECT * instead of providing those columns in select query, is there any performance degradation regarding more/less I/O or memory?
...
How to sort a dataframe by multiple column(s)
I want to sort a data.frame by multiple columns. For example, with the data.frame below I would like to sort by column z (descending) then by column b (ascending):
...
Creating a left-arrow button (like UINavigationBar's “back” style) on a UIToolbar
I'd love to create a "back" left-arrow-bezel button in a UIToolbar .
24 Answers
24
...
Why is a boolean 1 byte and not 1 bit of size?
...
12 Answers
12
Active
...
How to check if a string is a valid date
I have a string: "31-02-2010" and want to check whether or not it is a valid date.
What is the best way to do it?
14 Answ...
What are some compelling use cases for dependent method types?
Dependent method types, which used to be an experimental feature before, has now been enabled by default in the trunk , and apparently this seems to have created some excitement in the Scala community.
...
Why is Double.MIN_VALUE in not negative
Can anyone shed some light on why Double.MIN_VALUE is not actually the minimum value that Doubles can take? It is a positive value, and a Double can of course be negative.
...
Is there a simple way to convert C++ enum to string?
Suppose we have some named enums:
34 Answers
34
...