大约有 49,000 项符合查询结果（耗时：0.0665秒） [XML]
Ruby: Change negative number to positive number?
...
my answer is just for negative numbers, if you need to always have the absolute value then this is definitely the better way.
– Brandon Bodnar
Mar 19 '10 at 22:41
...
Which Eclipse files belong under version control?
...in - to force a reinitialization of the eclipse metadata. But this option, if checked, will remove your detailed launch parameters!)
project-dir/.project
project-dir/.classpath
project-dir/.settings/*
should be in your SCM (especially .project and .classpath according to the Eclipse documentatio...
How do I use the conditional operator (? :) in Ruby?
...C (the parenthesis are not required). It's an expression that works like:
if_this_is_a_true_value ? then_the_result_is_this : else_it_is_this
However, in Ruby, if is also an expression so: if a then b else c end === a ? b : c, except for precedence issues. Both are expressions.
Examples:
puts (...
What encoding/code page is cmd.exe using?
...sometimes they do not.
First of all, Unicode characters will only display if the
current console font contains the characters. So use
a TrueType font like Lucida Console instead of the default Raster Font.
But if the console font doesn’t contain the character you’re trying to display,
you’ll...
Fragments onResume from back stack
... FragmentManager manager = getSupportFragmentManager();
if (manager != null)
{
MyFragment currFrag = (MyFragment) manager.findFragmentById(R.id.fragmentItem);
currFrag.onFragmentResume();
} ...
How do I get around type erasure on Scala? Or, why can't I get the type parameter of my collections?
It's a sad fact of life on Scala that if you instantiate a List[Int], you can verify that your instance is a List, and you can verify that any individual element of it is an Int, but not that it is a List[Int], as can be easily verified:
...
Pass a data.frame column name to a function
...ley's Advanced R book is an excellent reference for some of these issues.
If you really want to save the user from typing all those quotes, one option might be to convert bare, unquoted column names to strings using deparse(substitute()):
new_column2 <- function(df,col_name,col1,col2){
col_...
Convert seconds to Hour:Minute:Second
...
H represents the amount of hours in a single day. So if you have 90000 seconds and you'll use H on it the result will be 01 (first hour of a next day). NOT 25 - there are only 24 hours in a day.
– MarcinWolny
Jun 20 '13 at 10:35
...
How should I escape commas and speech marks in CSV files so they work in Excel?
... to this.
Excel will only respect the escaping of commas and speech marks if the column value is NOT preceded by a space. So generating the file without spaces like this...
Reference,Title,Description
1,"My little title","My description, which may contain ""speech marks"" and commas."
2,"My other ...
How to get the last N records in mongodb?
...
If I understand your question, you need to sort in ascending order.
Assuming you have some id or date field called "x" you would do ...
.sort()
db.foo.find().sort({x:1});
The 1 will sort ascending (oldest to newest) an...