大约有 47,000 项符合查询结果(耗时:0.0561秒) [XML]

https://stackoverflow.com/ques... 

Remove a string from the beginning of a string

...gex: $prefix = 'bla_'; $str = 'bla_string_bla_bla_bla'; if (substr($str, 0, strlen($prefix)) == $prefix) { $str = substr($str, strlen($prefix)); } Takes: 0.0369 ms (0.000,036,954 seconds) And with: $prefix = 'bla_'; $str = 'bla_string_bla_bla_bla'; $str = preg_replace('/^' . preg_quote($p...
https://stackoverflow.com/ques... 

Math.random() versus Random.nextInt(int)

...tributed bits in its mantissa, so it is uniformly distributed in the range 0 to 1-(2^-53). Random.nextInt(n) uses Random.next() less than twice on average- it uses it once, and if the value obtained is above the highest multiple of n below MAX_INT it tries again, otherwise is returns the value ...
https://stackoverflow.com/ques... 

How to find the sum of an array of numbers

... how can I find the sum of its elements? (In this case, the sum would be 10 .) 43 Answers ...
https://stackoverflow.com/ques... 

How to pass optional arguments to a method in C++?

...e of passing mode as optional parameter void myfunc(int blah, int mode = 0) { if (mode == 0) do_something(); else do_something_else(); } you can call myfunc in both ways and both are valid myfunc(10); // Mode will be set to default 0 myfunc(10, 1); // Mode will be ...
https://stackoverflow.com/ques... 

Running a cron job at 2:30 AM everyday

How to configure a cron job to run every night at 2:30? I know how to make it run at 2, but not 2:30. 6 Answers ...
https://stackoverflow.com/ques... 

How to use shared memory with Linux in C

...lains their purpose. return mmap(NULL, size, protection, visibility, -1, 0); } The following is an example program that uses the function defined above to allocate a buffer. The parent process will write a message, fork, and then wait for its child to modify the buffer. Both processes can read a...
https://stackoverflow.com/ques... 

SQL keys, MUL vs PRI vs UNI

...at column. – pgoetz Aug 7 '19 at 16:07 add a comment  |  ...
https://stackoverflow.com/ques... 

.toArray(new MyClass[0]) or .toArray(new MyClass[myList.size()])?

...est version, on Hotspot 8, is: MyClass[] arr = myList.toArray(new MyClass[0]); I have run a micro benchmark using jmh the results and code are below, showing that the version with an empty array consistently outperforms the version with a presized array. Note that if you can reuse an existing arr...
https://stackoverflow.com/ques... 

How to get the first element of an array?

... like this alert(ary[0]) share | improve this answer | follow | ...
https://stackoverflow.com/ques... 

Can PNG image transparency be preserved when using PHP's GDlib imagecopyresampled?

... 10 Answers 10 Active ...