大约有 47,000 项符合查询结果（耗时：0.0483秒） [XML]
How to check iOS version?
...lable(iOS 9, *) {}
In Objective-C, you need to check the system version and perform a comparison.
[[NSProcessInfo processInfo] operatingSystemVersion] in iOS 8 and above.
As of Xcode 9:
if (@available(iOS 9, *)) {}
The full answer …
In Objective-C, and Swift in rare cases, it's better to...
How do you use “
I just finished reading about scoping in the R intro , and am very curious about the <<- assignment.
6 Answers
...
How to extract numbers from a string and get an array of ints?
...able (basically an English sentence with an unspecified number of numbers) and I'd like to extract all the numbers into an array of integers. I was wondering whether there was a quick solution with regular expressions?
...
How efficient is locking an unlocked mutex? What is the cost of a mutex?
...bunch of mutexes or a single one for an object.
If you have many threads and the access to the object happens often, then multiple locks would increase parallelism. At the cost of maintainability, since more locking means more debugging of the locking.
How efficient is it to lock a mutex? I.e....
What is an intuitive explanation of the Expectation Maximization technique? [closed]
... here.
Suppose we have some data sampled from two different groups, red and blue:
Here, we can see which data point belongs to the red or blue group. This makes it easy to find the parameters that characterise each group. For example, the mean of the red group is around 3, the mean of the blue...
XSD - how to allow elements in any order any number of times?
I am trying to create an XSD, and trying to write the definition with the following requirement:
6 Answers
...
How to check if a variable is an integer in JavaScript?
How do I check if a variable is an integer in JavaScript, and throw an alert if it isn't? I tried this, but it doesn't work:
...
How can I use goto in Javascript?
...led Summer of Goto that allows you use JavaScript at its fullest potential and will revolutionize the way you can write your code.
This JavaScript preprocessing tool allows you to create a label and then goto it using this syntax:
[lbl] <label-name>
goto <label-name>
For example, the ex...
Generate random numbers using C++11 random library
As the title suggests, I am trying to figure out a way of generating random numbers using the new C++11 <random> library. I have tried it with this code:
...
Java synchronized static methods: lock on object or class
...
Please answer Elaborate so that everyone can understand.
– Madhu
Sep 2 '09 at 4:49
6
...