大约有 44,677 项符合查询结果（耗时：0.0325秒） [XML]
How to delete migration files in Rails 3
...:migrate again.
If your application is already on production or staging, it's safer to just write another migration that destroys your table or columns.
Another great reference for migrations is: http://guides.rubyonrails.org/migrations.html
...
What is the equivalent of the C++ Pair in Java?
... do you know what "first" and "second" mean ?).
A better practice is to write a very simple class, like the one Mike proposed, for each application you would have made of the Pair class. Map.Entry is an example of a pair that carry its meaning in its name.
To sum up, in my opinion it is better to ...
Bootstrap 3 Navbar with Logo
I want to use the Bootstrap 3 default navbar with an image logo instead of text branding. What's the proper way of doing this without causing any issues with different screen sizes? I assume this a common requirement, but I haven't yet seen a good code sample. A key requirement other than having acc...
How to loop through array in jQuery?
...ptions much more thoroughly. The third option below, jQuery.each, isn't in it though.)
Four options:
Generic loop:
var i;
for (i = 0; i < substr.length; ++i) {
// do something with `substr[i]`
}
or in ES2015+:
for (let i = 0; i < substr.length; ++i) {
// do something with `subs...
How do I size a UITextView to its content?
Is there a good way to adjust the size of a UITextView to conform to its content? Say for instance I have a UITextView that contains one line of text:
...
Indenting #defines
...e line but they didn't require de preprocessor directive to be attached to it, so indentation was made this way.
#ifdef SDCC
# if DEBUGGING == 1
# if defined (pic18f2480)
# define FLASH_MEMORY_END 0x3DC0
# elif defined (pic18f2580)
# define FLASH_MEMORY_END 0x7DC0
# else
# ...
What is the purpose of “return await” in C#?
Is there any scenario where writing method like this:
7 Answers
7
...
What's the difference between echo, print, and print_r in PHP?
...play strings. The differences are subtle: print has a return value of 1 so it can be used in expressions whereas echo has a void return type; echo can take multiple parameters, although such usage is rare; echo is slightly faster than print. (Personally, I always use echo, never print.)
var_dump pr...
git rebase: “error: cannot stat 'file': Permission denied”
I'm using git, and made a small commit followed by a large one. I decided to use git rebase to squash the two commits together before pushing them. (I've never done this before.)
...
What is a serialVersionUID and why should I use it?
...od an explanation as you'll get:
The serialization runtime associates with each serializable class a version number, called a serialVersionUID, which is used during deserialization to verify that the sender and receiver of a serialized object have loaded classes for that object that are compatib...