大约有 48,000 项符合查询结果（耗时：0.0512秒） [XML]
How can I repeat a character in Bash?
...
You can use:
printf '=%.0s' {1..100}
How this works:
Bash expands {1..100} so the command becomes:
printf '=%.0s' 1 2 3 4 ... 100
I've set printf's format to =%.0s which means that it will always print a single = no matter what argument it is given. Therefore it prints 100 =s.
...
Test if characters are in a string
...
@GregSnow -- Tried system.time(a <- grepl("abc", vec)) and system.time(a <- grepl("abc", vec, fixed=TRUE)), and fixed=TRUE is still, if anything slightly slower. The difference isn't appreciable with these short strings, but fixed=TRUE still doesn't seem to be faster. Thanks ...
Underscore: sortBy() based on multiple attributes
...atient[0].roomNumber;
}).value();
When the second sortBy finds that John and Lisa have the same room number it will keep them in the order it found them, which the first sortBy set to "Lisa, John".
share
|
...
jQuery deferreds and promises - .then() vs .done()
I've been reading about jQuery deferreds and promises and I can't see the difference between using .then() & .done() for successful callbacks. I know Eric Hynds mentions that .done() and .success() map to the same functionality but I'm guessing so does .then() as all the callbacks are al...
DateTime2 vs DateTime in SQL Server
...datetime2. Here is their recommendation:
Use the time, date, datetime2 and
datetimeoffset data types for new
work. These types align with the SQL
Standard. They are more portable.
time, datetime2 and datetimeoffset
provide more seconds precision.
datetimeoffset provides time zone
s...
Should I use #define, enum or const?
.... Those four flags can be combined. Flags describe the records in database and can be:
15 Answers
...
Using python map and other functional tools
This is quite n00bish, but I'm trying to learn/understand functional programming in python. The following code:
9 Answers
...
Is there a difference between foreach and map?
...n a particular language, but is there a difference between a map operation and a foreach operation? Or are they simply different names for the same thing?
...
Proper stack and heap usage in C++?
I've been programming for a while but It's been mostly Java and C#. I've never actually had to manage memory on my own. I recently began programming in C++ and I'm a little confused as to when I should store things on the stack and when to store them on the heap.
...
Vagrant stuck connection timeout retrying
...g perfectly fine last night. I've just turned the PC on, hit vagrant up , and this is what I get:
47 Answers
...