大约有 40,000 项符合查询结果（耗时：0.0746秒） [XML]
Remove duplicated rows using dplyr
... @hadley I like the unique() and distinct() function, however, they all remove the 2nd duplicate from the data frame. what if I want to have all 1st encounters of the duplicate value removed? How could this be done? Thanks for any help!
– FlyingDutch
Feb...
Child with max-height: 100% overflows parent
... child's max-height to be calculated from, so max-height computes to none, allowing the child to be as tall as possible. The only other constraint acting on the child now is the max-width of its parent, and since the image itself is taller than it is wide, it overflows the container's height downwar...
git: difference between “branchname” and “refs/heads/branchname”
...ee heads, remotes, and tags in your .git/refs directory, assuming you have all three types of refs in your repository.
refs/heads/0.58 specifies a branch named 0.58. If you don't specify what namespace the ref is in, git will look in the default ones. This makes using only 0.58 conceivably ambiguous...
How to make the first option of selected with jQuery
...l($("#target option:first").val()); will work in IE6, because you are literally looking up the first value, and entering it as target's value. Two id lookups instead of one.
– Nicholi
Feb 4 '12 at 1:56
...
Rails: Default sort order for a rails model?
...ow use Book.published.confirmed.
With this method, the query is not actually executed until actual results are needed (lazy evaluation), so 7 scopes could be chained together but only resulting in 1 actual database query, to avoid performance problems from executing 7 separate queries.
You can u...
How do negative margins in CSS work and why is (margin-top:-5 != margin-bottom:5)?
...way to go (as opposed to articles like this)? I see you're trying to vertically center the element, so why do you have to set margin-top:-8px; and not margin-top:-50%;?
Well, vertical centering in CSS is harder than it should be. When setting even top or bottom margins in %, the value is calculated...
Quick-and-dirty way to ensure only one instance of a shell script is running at a time
... signal but just checks if a process with the given PID exists. Also the call to trap will ensure that the lockfile is removed even when your process is killed (except kill -9).
share
|
improve thi...
Automatic prune with Git fetch or pull
... work is over and I don't know, I won't do a git fetch --prune and eventually I will push back the deleted branch.
3 Answ...
C# int to byte[]
...sides, doing the assignment is cheap since it does not copy the memory nor allocate new memory, it just adds a new name to the already allocated array. So why not do it?
– paracycle
May 7 '19 at 15:54
...
What is the fastest way to compare two sets in Java?
...
firstSet.equals(secondSet)
It really depends on what you want to do in the comparison logic... ie what happens if you find an element in one set not in the other? Your method has a void return type so I assume you'll do the necessary work in this method.
M...