大约有 48,000 项符合查询结果（耗时：0.0720秒） [XML]
Rails 3: Get Random Record
So, I've found several examples for finding a random record in Rails 2 -- the preferred method seems to be:
14 Answers
...
What is the strict aliasing rule?
... ability to give aliasing warnings, sometimes giving us a friendly warning and sometimes not.)
To see why this behavior is undefined, we have to think about what the strict aliasing rule buys the compiler. Basically, with this rule, it doesn't have to think about inserting instructions to refresh th...
Optimal number of threads per core
Let's say I have a 4-core CPU, and I want to run some process in the minimum amount of time. The process is ideally parallelizable, so I can run chunks of it on an infinite number of threads and each thread takes the same amount of time.
...
Remove empty elements from an array in Javascript
...that are falsy, which include an empty string "", 0, NaN, null, undefined, and false.
You can pass to the filter method, the Boolean constructor function, or return the same element in the filter criteria function, for example:
var filtered = array.filter(Boolean);
Or
var filtered = array.filte...
Performance of foreach, array_map with lambda and array_map with static function
...2 compare with mcfedr's answer below for additional results without XDebug and a more recent PHP version.
function lap($func) {
$t0 = microtime(1);
$numbers = range(0, 1000000);
$ret = $func($numbers);
$t1 = microtime(1);
return array($t1 - $t0, $ret);
}
function useForeach($numbers) {...
How to convert all tables from MyISAM into InnoDB?
...N_SCHEMA.TABLES
WHERE TABLE_SCHEMA = 'your_database_name'
AND ENGINE = 'MyISAM'";
$rs = mysql_query($sql);
while($row = mysql_fetch_array($rs))
{
$tbl = $row[0];
$sql = "ALTER TABLE `$tbl` ENGINE=INNODB";
mysql_query($sql);
}
?>
...
Can you do this HTML layout without using tables?
...wrong with using the tools that are available to you to do the job quickly and correctly.
In this case a table worked perfectly.
I personally would have used a table for this.
I think nested tables should be avoided, things can get messy.
...
How can I close a Twitter Bootstrap popover with a click from anywhere (else) on the page?
...y time, you can use a set of flags to mark when there's a popover visible, and only then hide them.
If you set the event listener on the document body, it will trigger when you click the element marked with 'popup-marker'. So you'll have to call stopPropagation() on the event object. And apply the ...
How to set versionName in APK filename using gradle?
...g on the build variant selected.
Note that this solution works on both APK and App Bundles (.aab files).
See Also: How to change the proguard mapping file name in gradle for Android project
#Solution for Recent Gradle Plugin
android {
compileSdkVersion 22
buildToolsVersion "22.0.1"
defau...
Comprehensive beginner's virtualenv tutorial? [closed]
I've been hearing the buzz about virtualenv lately, and I'm interested. But all I've heard is a smattering of praise, and don't have a clear understanding of what it is or how to use it.
...