大约有 43,000 项符合查询结果（耗时：0.0564秒） [XML]
Condition within JOIN or WHERE
...u only those records that have an order dated later than May 15, 2009 thus converting the left join to an inner join.
The second will give those records plus any customers with no orders. The results set is very different depending on where you put the condition. (Select * is for example purposes on...
What does the “map” method do in Ruby?
...example:
names = ['danil', 'edmund']
# here we map one array to another, convert each element by some rule
names.map! {|name| name.capitalize } # now names contains ['Danil', 'Edmund']
names.each { |name| puts name + ' is a programmer' } # here we just do something with each element
The output:...
C/C++中的段错误（Segmentation fault） - C/C++ - 清泛网 - 专注C/C++及内核技术
...ress or Bus errors.
Segmentation is one approach to memory management and protection in the operating system. It has been superseded by paging for most purposes, but much of the terminology of segmentation is still used, "segmentation fault" being an example. Some operating systems still have s...
Easy way to concatenate two byte arrays
...u simply add the line outputStream.write( c ); - you don't have to go back and edit the line where you create the result byte array. Also, re-ordering the arrays is simple, unlike using the arraycopy method.
– Wayne Uroda
Aug 27 '12 at 11:38
...
Make a negative number positive
...
The concept you are describing is called "absolute value", and Java has a function called Math.abs to do it for you. Or you could avoid the function call and do it yourself:
number = (number < 0 ? -number : number);
or
if (number < 0)
number = -number;
...
How can I count the number of matches for a regex?
...r Java 9+
long matches = matcher.results().count();
Solution for Java 8 and older
You'll have to do the following. (Starting from Java 9, there is a nicer solution)
int count = 0;
while (matcher.find())
count++;
Btw, matcher.groupCount() is something completely different.
Complete exampl...
How to get element by innerText
...electorAll(haystack), 0);
}
// if haystack has a length property, we convert it to an Array
// (if it's already an array, this is pointless, but not harmful):
else if (haystack.length) {
elems = [].slice.call(haystack, 0);
}
// work out whether we're looking at innerText (IE...
What is the difference between i++ and ++i?
I've seen them both being used in numerous pieces of C# code, and I'd like to know when to use i++ or ++i ( i being a number variable like int , float , double , etc). Anyone who knows this?
...
ObservableCollection Doesn't support AddRange method, so I get notified for each item added, besides
I want to be able to add a range and get updated for the entire bulk.
12 Answers
12
...
Android read text raw resource file
...for large resources. It depends on the size of the inputstream read buffer and could only return a part of the resource.
– d4n3
Jun 29 '12 at 6:19
6
...