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Is a `=default` move constructor equivalent to a member-wise move constructor?
...mber function,
have the same declared function type (except for possibly differing ref-qualifiers and except that in the case of a copy constructor or copy assignment operator, the parameter type may be “reference to non-const T”, where T is the name of the member function’s class) as if it h...
How do I insert NULL values using PDO?
...
I'm not sure the difference between those two, but I'll investigate some. Thanks, your answer was great too.
– Nacho
Sep 8 '09 at 3:29
...
What is tail recursion?
...e JavaScript implementation that uses recursion:
function recsum(x) {
if (x === 1) {
return x;
} else {
return x + recsum(x - 1);
}
}
If you called recsum(5), this is what the JavaScript interpreter would evaluate:
recsum(5)
5 + recsum(4)
5 + (4 + recsum(3))
5 + (4 + ...
How do I check if a variable exists in a list in BASH
...
May give false positive if the user input contains regular expression special characters, for example x=.
– glenn jackman
Nov 9 '11 at 11:41
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Find an item in List by LINQ?
...list).
1) Single will return a single result, but will throw an exception if it finds none or more than one (which may or may not be what you want):
string search = "lookforme";
List<string> myList = new List<string>();
string result = myList.Single(s => s == search);
Note SingleO...
How to use php serialize() and unserialize()
...e transported or stored or otherwise used outside of a running PHP script. If you want to persist such a complex data structure beyond a single run of a script, you need to serialize it. That just means to put the structure into a "lower common denominator" that can be handled by things other than P...
Is 'switch' faster than 'if'?
Is a switch statement actually faster than an if statement?
12 Answers
12
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“ValueError: zero length field name in format” error in Python 3.0,3.1,3.2
I'm trying learn Python (3 to be more specific) and I'm getting this error:
3 Answers
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How to select the row with the maximum value in each group
...solution:
require(data.table) ## 1.9.2
group <- as.data.table(group)
If you want to keep all the entries corresponding to max values of pt within each group:
group[group[, .I[pt == max(pt)], by=Subject]$V1]
# Subject pt Event
# 1: 1 5 2
# 2: 2 17 2
# 3: 3 5 ...
The difference between bracket [ ] and double bracket [[ ]] for accessing the elements of a list or
R provides two different methods for accessing the elements of a list or data.frame: [] and [[]] .
12 Answers
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