大约有 15,000 项符合查询结果（耗时：0.0326秒） [XML]
Difference between fprintf, printf and sprintf?
...on>
#include <stdarg.h>
#include <stdio.h>
struct exception_fmt : std::exception
{
exception_fmt(char const* fmt, ...) __attribute__ ((format(printf,2,3)));
char const* what() const throw() { return msg_; }
char msg_[0x800];
};
exception_fmt::exception_fmt(char const* fm...
How to redirect to a 404 in Rails?
...tionality built in already. If you want to show a 404 page, create a render_404 method (or not_found as I called it) in ApplicationController like this:
def not_found
raise ActionController::RoutingError.new('Not Found')
end
Rails also handles AbstractController::ActionNotFound, and ActiveReco...
How can I rename a field for all documents in MongoDB?
...ormer way:
remap = function (x) {
if (x.additional){
db.foo.update({_id:x._id}, {$set:{"name.last":x.name.additional}, $unset:{"name.additional":1}});
}
}
db.foo.find().forEach(remap);
In MongoDB 3.2 you can also use
db.students.updateMany( {}, { $rename: { "oldname": "newname" } } )
...
cancelling a handler.postdelayed process
... this to post a delayed runnable:
myHandler.postDelayed(myRunnable, SPLASH_DISPLAY_LENGTH);
And this to remove it: myHandler.removeCallbacks(myRunnable);
share
|
improve this answer
|
...
Django database query: How to get object by id?
...ject, using get() is more straightforward:
obj = Class.objects.get(pk=this_object_id)
share
|
improve this answer
|
follow
|
...
How to find the operating system version using JavaScript?
...dows 3.11' => 'Win16',
'Windows 95' => '(Windows 95)|(Win95)|(Windows_95)',
'Windows 98' => '(Windows 98)|(Win98)',
'Windows 2000' => '(Windows NT 5.0)|(Windows 2000)',
'Windows XP' => '(Windows NT 5.1)|(Windows XP)',
'Windows Server 2003' => '(Windows NT 5.2)',
'Windows Vista' =&g...
Run a single migration file
...f the ruby file:
rails console
>> require "db/migrate/20090408054532_add_foos.rb"
>> AddFoos.up
Note: newer versions of rails may require AddFoos.new.up rather than AddFoos.up.
An alternative way (without IRB) which relies on the fact that require returns an array of class names:
sc...
How do you know when to use fold-left and when to use fold-right?
...ee it. It's "haskell-style pseudocode". :)
– laughing_man
Apr 21 '15 at 2:38
...
How do I check if there are duplicates in a flat list?
...e set() to remove duplicates if all values are hashable:
>>> your_list = ['one', 'two', 'one']
>>> len(your_list) != len(set(your_list))
True
share
|
improve this answer
...
How do I install an R package from source?
...hen use install.packages() and set the repos=NULL:
install.packages(path_to_file, repos = NULL, type="source")
Where path_to_file would represent the full path and file name:
On Windows it will look something like this: "C:\\RJSONIO_0.2-3.tar.gz".
On UNIX it will look like this: "/home/blah/R...