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Remove rows with all or some NAs (missing values) in data.frame
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but using complete.cases is quite a lot more clear, and faster.
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What is the difference between SQL, PL-SQL and T-SQL?
What is the difference between SQL, PL-SQL and T-SQL?
6 Answers
6
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initializer_list and move semantics
...ist existed to keep an array of temporaries until they were move'd.
begin and end for initializer_list return const T *, so the result of move in your code is T const && — an immutable rvalue reference. Such an expression can't meaningfully be moved from. It will bind to an function param...
Help with C# generics error - “The type 'T' must be a non-nullable value type”
I'm new to C# and don't understand why the following code doesn't work.
4 Answers
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When to use IList and when to use List
I know that IList is the interface and List is the concrete type but I still don't know when to use each one. What I'm doing now is if I don't need the Sort or FindAll methods I use the interface. Am I right? Is there a better way to decide when to use the interface or the concrete type?
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php is null or empty?
...===.
When use ==, as you did, PHP treats NULL, false, 0, the empty string, and empty arrays as equal.
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Java: Instanceof and Generics
...Object(Class<T> type) {
return new MyObject<T>(type);
}
And then in the object's constructor store that type, so variable so that your method could look like this:
if (arg0 != null && !(this.type.isAssignableFrom(arg0.getClass()))
{
return -1;
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No ConcurrentList in .Net 4.0?
...ncurrentDictionary , ConcurrentQueue , ConcurrentStack , ConcurrentBag and BlockingCollection .
11 Answers
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Regex: match everything but specific pattern
... but a string starting with a specific pattern (specifically index.php and what follows, like index.php?id=2342343 )
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Calculate the median of a billion numbers
If you have one billion numbers and one hundred computers, what is the best way to locate the median of these numbers?
25 A...