大约有 48,000 项符合查询结果（耗时：0.0430秒） [XML]
What is the difference between persist() and merge() in JPA and Hibernate?
What is the difference between persist() and merge() in Hibernate?
4 Answers
4
...
How do browsers pause/change Javascript when tab or window is not active?
...st is quite CPU intensive. requestAnimationFrame is not supported by IE 9- and Opera 12-.
The test logs the actual time it takes for a setInterval and requestAnimationFrame to run in different browsers, and gives you the results in the form of a distribution. You can change the number of millisecon...
Mixing Angular and ASP.NET MVC/Web api?
I come from using ASP.NET MVC/Web API and now I am starting to use Angular but I am not clear on the proper way to mix them.
...
Why doesn't c++ have &&= or ||= for booleans?
Is there a "very bad thing" that can happen &&= and ||= were used as syntactic sugar for bool foo = foo && bar and bool foo = foo || bar ?
...
What are the undocumented features and limitations of the Windows FINDSTR command?
The Windows FINDSTR command is horribly documented. There is very basic command line help available through FINDSTR /? , or HELP FINDSTR , but it is woefully inadequate. There is a wee bit more documentation online at https://docs.microsoft.com/en-us/windows-server/administration/windows-commands...
Is Python strongly typed?
...older dialects of C, which were weakly, statically typed, so that pointers and integers were pretty much interchangeable. (Modern ISO C requires conversions in many cases, but my compiler is still lenient about this by default.)
I must add that the strong vs. weak typing is more of a continuum than...
Check synchronously if file/directory exists in Node.js
...version of lstat, etc.
lstatSync tells you both whether something exists, and if so, whether it's a file or a directory (or in some file systems, a symbolic link, block device, character device, etc.), e.g. if you need to know if it exists and is a directory:
var fs = require('fs');
try {
// Q...
Which is more efficient, a for-each loop, or an iterator?
...
If you are just wandering over the collection to read all of the values, then there is no difference between using an iterator or the new for loop syntax, as the new syntax just uses the iterator underwater.
If however, you mean by loop the ...
Does const mean thread-safe in C++11?
...ad-safe in C++11. Is that true?
It is somewhat true...
This is what the Standard Language has to say on thread-safety:
[1.10/4]
Two expression evaluations conflict if one of them modifies a memory location (1.7) and the other one accesses or modifies the same memory location.
[1.10/21]
The executi...
Redis: possible to expire an element in an array or sorted set?
...tire key/value pair? What if I want to add values to a List type structure and have them get auto removed 1 hour after insertion. Is that currently possible, or would it require running a cron job to do the purging manually?
...