大约有 40,000 项符合查询结果（耗时：0.0619秒） [XML]
What is the purpose of setting a key in data.table?
...e other vignettes that we plan to.
I've updated this answer again (Feb 2016) in light of the new on= feature that allows ad-hoc joins as well. See history for earlier (outdated) answers.
What exactly does setkey(DT, a, b) do?
It does two things:
reorders the rows of the data.table DT by the...
How to compare two NSDates: Which is more recent?
...
660
Let's assume two dates:
NSDate *date1;
NSDate *date2;
Then the following comparison will tell...
Clear file cache to repeat performance testing
... |
edited Nov 13 '12 at 5:05
Jeff Atwood
59.8k4545 gold badges146146 silver badges149149 bronze badges
a...
boolean in an if statement
...== entirely.
As an example of how confusing it can be:
var x;
x = 0;
console.log(x == true); // false, as expected
console.log(x == false); // true as expected
x = 1;
console.log(x == true); // true, as expected
console.log(x == false); // false as expected
x = 2;
console.l...
Fast way of finding lines in one file that are not in another?
I have two large files (sets of filenames). Roughly 30.000 lines in each file. I am trying to find a fast way of finding lines in file1 that are not present in file2.
...
How to pause a YouTube player when hiding the iframe?
...ementById("popupVid");
var iframe = div.getElementsByTagName("iframe")[0].contentWindow;
div.style.display = state == 'hide' ? 'none' : '';
func = state == 'hide' ? 'pauseVideo' : 'playVideo';
iframe.postMessage('{"event":"command","func":"' + func + '","args":""}', '*');
}
</scri...
Bootstrap: Open Another Modal in Modal
...
20 Answers
20
Active
...
How do I generate random integers within a specific range in Java?
...
+150
In Java 1.7 or later, the standard way to do this is as follows:
import java.util.concurrent.ThreadLocalRandom;
// nextInt is normal...
Edit line thickness of CSS 'underline' attribute
...
10 Answers
10
Active
...
Adjust UILabel height depending on the text
...
409
sizeWithFont constrainedToSize:lineBreakMode: is the method to use. An example of how to use it...