大约有 47,000 项符合查询结果（耗时：0.0518秒） [XML]
Get a random item from a JavaScript array [duplicate]
... not a valid substitution for Math.floor. Using round would cause accidentally referencing an undefined index, say in the case Math.random() is 0.95 and items.length is 5. Math.round(0.95*5) is 5, which would be an invalid index. floor(random) will always be zero in your example.
...
What is `related_name` used for in Django?
... back to your model.
If you don't specify a related_name, Django automatically creates one using the name of your model with the suffix _set, for instance User.map_set.all().
If you do specify, e.g. related_name=maps on the User model, User.map_set will still work, but the User.maps. syntax is ob...
【内核源码】linux UDP实现 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
...
.rehash = udp_v4_rehash,
.get_port = udp_v4_get_port,
.memory_allocated = &udp_memory_allocated,
.sysctl_mem = sysctl_udp_mem,
.sysctl_wmem = &sysctl_udp_wmem_min,
.sysctl_rmem = &sysctl_udp_rmem_min,
.obj_size = sizeof(struct udp_sock),
.h.udp_table = &udp_tab...
Facebook share link without JavaScript
...ove it (the onclick part) ... and it will still work. But I can see how it all not 100% clear ... I'll edit it.
– King'ori Maina
Feb 26 '14 at 16:03
2
...
Simple example of threading in C++
...ill execute, followed by the function's parameters. The thread is automatically started upon construction.
If later on you want to wait for the thread to be done executing the function, call:
t1.join();
(Joining means that the thread who invoked the new thread will wait for the new thread to fi...
What is an example of the simplest possible Socket.io example?
...ovided this answer. That being said, here is the original answer updated small-small for the newer API.
Just because I feel nice today:
index.html
<!doctype html>
<html>
<head>
<script src='/socket.io/socket.io.js'></script>
<script>
...
How to delete duplicate lines in a file without sorting it in Unix?
... To save it in a file we can do this awk '!seen[$0]++' merge_all.txt > output.txt
– Akash Kandpal
Jul 19 '18 at 11:42
5
...
std::unique_ptr with an incomplete type won't compile
...
I find your first solution (adding the foo destructor) allows the class declaration itself to compile, but declaring an object of that type anywhere results in the original error ("invalid application of 'sizeof'...").
– Jeff Trull
Sep 30 '1...
Image Greyscale with CSS & re-color on mouse-over?
...rayscale(100%);
/* Chrome 19+ & Safari 6+ */
-webkit-transition: all .6s ease;
/* Fade to color for Chrome and Safari */
-webkit-backface-visibility: hidden;
/* Fix for transition flickering */
}
img.grayscale:hover {
filter: none;
-webkit-filter: grayscale(0%);
}
sv...
Rank function in MySQL
... (SELECT @curRank := 0) r
ORDER BY age;
The (SELECT @curRank := 0) part allows the variable initialization without requiring a separate SET command.
Test case:
CREATE TABLE person (id int, first_name varchar(20), age int, gender char(1));
INSERT INTO person VALUES (1, 'Bob', 25, 'M');
INSERT I...