大约有 41,000 项符合查询结果（耗时：0.0431秒） [XML]
How to validate an email address in PHP
...
The easiest and safest way to check whether an email address is well-formed is to use the filter_var() function:
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
// invalid emailaddress
}
Additionally you can check whether the do...
Are duplicate keys allowed in the definition of binary search trees?
I'm trying to find the definition of a binary search tree and I keep finding different definitions everywhere.
12 Answers
...
What is “android:allowBackup”?
...e, either open the lint warnings view, where you can select the lint error and see a longer explanation, or invoke the quick fix (Ctrl-1) on the error line, and one of the suggestions is "Explain this issue", which will also pop up a fuller explanation. If you are not using Eclipse, you can generate...
Visual Studio 2013 doesn't discover unit tests
...isual studio 2013 that is composed by one web project, one library project and one unit test project. When I open the solution and try to run the unit tests they are not discover by visual studio. To run the tests I try to go to the menu and choose Test -> Run -> Run all tests or by opening the test...
How to map and remove nil values in Ruby
...
Ruby 2.7 is introducing filter_map for this exact purpose. It's idiomatic and performant, and I'd expect it to become the norm very soon.
For example:
numbers = [1, 2, 5, 8, 10, 13]
enum.filter_map { |i| i * 2 if i.even? }
# => [4, 16, 20]
In your case, as the block evaluates to falsey, simp...
SQL Server - Create a copy of a database table and place it in the same database?
...is will create a new table ABC_1 that has the same column structure as ABC and contains the same data. Constraints (e.g. keys, default values), however, are -not- copied.
You can run this query multiple times with a different table name each time.
If you don't need to copy the data, only to cre...
Difference between Role and GrantedAuthority in Spring Security
There are concepts and implementations in Spring Security, such as the GrantedAuthority interface to get an authority to authorize/control an access.
...
What's the -practical- difference between a Bare and non-Bare repository?
I've been reading about the bare and non-bare / default repositores in Git. I haven't been able to understand quite well (theoretically) about the differences between them, and why I should "push" to a bare repository. Here's the deal:
...
Why is a combiner needed for reduce method that converts type in java 8
I'm having trouble fully understanding the role that the combiner fulfils in Streams reduce method.
4 Answers
...
What is java interface equivalent in Ruby?
Can we expose interfaces in Ruby like we do in java and enforce the Ruby modules or classes to implement the methods defined by interface.
...