大约有 31,840 项符合查询结果（耗时：0.0177秒） [XML]
PHP Pass by reference in foreach [duplicate]
...t's overwritten each time.
You can see it like that:
$a = array ('zero','one','two', 'three');
foreach ($a as &$v) {
}
foreach ($a as $v) {
echo $v.'-'.$a[3].PHP_EOL;
}
As you can see, the last array item takes the current loop value: 'zero', 'one', 'two', and then it's just 'two'... : ...
How can I parse a CSV string with JavaScript, which contains comma in data?
...
Disclaimer
2014-12-01 Update: The answer below works only for one very specific format of CSV. As correctly pointed out by DG in the comments, this solution does not fit the RFC 4180 definition of CSV and it also does not fit Microsoft Excel format. This solution simply demonstrates how...
Which is more efficient: Multiple MySQL tables or one large table?
...up a new system, it almost makes sense to combine all of these tables into one big table of related content.
8 Answers
...
Why is there “data” and “newtype” in Haskell? [duplicate]
...ition is just a data definition that obeys some restrictions (e.g., only one constructor), and that due to these restrictions the runtime system can handle newtype s more efficiently. And the handling of pattern matching for undefined values is slightly different.
...
MongoDB: Combine data from multiple collections into one..how?
How can I (in MongoDB) combine data from multiple collections into one collection?
11 Answers
...
Can a foreign key be NULL and/or duplicate?
...e that stores sales proposals. Suppose further that each proposal only has one sales person assigned and one client. So your proposal table would have two foreign keys, one with the client ID and one with the sales rep ID. However, at the time the record is created, a sales rep is not always assig...
What are the best practices for SQLite on Android?
...get corrupted.
The basic answer.
The SqliteOpenHelper object holds on to one database connection. It appears to offer you a read and write connection, but it really doesn't. Call the read-only, and you'll get the write database connection regardless.
So, one helper instance, one db connection. ...
Sibling package imports
...tempted to handle imports in a more rational way but Guido has rejected it one the account of
The only use case seems to be running scripts that happen
to be living inside a module's directory, which I've always seen as an
antipattern.
(here)
Though, I use this pattern on a regular basis ...
Implementing Comments and Likes in database
...
The most extensible solution is to have just one "base" table (connected to "likes", tags and comments), and "inherit" all other tables from it. Adding a new kind of entity involves just adding a new "inherited" table - it then automatically plugs into the whole like/ta...
Can someone explain mappedBy in JPA and Hibernate?
I am new to hibernate and need to use one-to-many and many-to-one relations. It is a bi-directional relationship in my objects, so that I can traverse from either direction. mappedBy is the recommended way to go about it, however, I couldn't understand it. Can someone explain:
...