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Type converting slices of interfaces
...n: https://github.com/golang/go/wiki/InterfaceSlice
var dataSlice []int = foo()
var interfaceSlice []interface{} = make([]interface{}, len(dataSlice))
for i, d := range dataSlice {
interfaceSlice[i] = d
}
share
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Conditionally Remove Dataframe Rows with R [duplicate]
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Actually, a simpler way of viewing it is: foo.isolated <- subset(foo, !(sid == "sid104" & game.num == 7))
– WGray
Aug 6 '15 at 21:01
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What’s the purpose of prototype? [duplicate]
...-created each time; it exists in one place in the prototype. So when you call someAnimal.set_name("Ubu"); the this context will be set to someAnimal and (the one and only) set_name function will be called.
There is one advantage to using the first syntax though: functions created in this manner...
How to create arguments for a Dapper query dynamically
...ffer a full example here.
string query = "SELECT * FROM MyTableName WHERE Foo = @Foo AND Bar = @Bar";
Dictionary<string, object> dictionary = new Dictionary<string, object>();
dictionary.Add("@Foo", "foo");
dictionary.Add("@Bar", "bar");
var results = connection.Query<MyTableName&g...
php is null or empty?
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As is shown in the following table, empty($foo) is equivalent to $foo==null and is_null($foo) has the same function of $foo===null. The table also shows some tricky values regarding the null comparison. (ϕ denotes an uninitialized variables. )
empty is_n...
What is more efficient? Using pow to square or just multiply it with itself?
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I tested the performance difference between x*x*... vs pow(x,i) for small i using this code:
#include <cstdlib>
#include <cmath>
#include <boost/date_time/posix_time/posix_time.hpp>
inline boost::posix_time::ptime now()
{
return boost::posix_time::microsec_clock::local_t...
Using global variables in a function
...ce global variables are so dangerous, Python wants to make sure that you really know that's what you're playing with by explicitly requiring the global keyword.
See other answers if you want to share a global variable across modules.
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Function overloading by return type?
Why don't more mainstream statically typed languages support function/method overloading by return type? I can't think of any that do. It seems no less useful or reasonable than supporting overload by parameter type. How come it's so much less popular?
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Get property value from string using reflection
...fferentiate between a null value of an existing property or no property at all? I'd much rather know immediately that I was sending in a bad property name. This is not production code, but a better improvement would be to throw a more specific exception (e.g. check for null on GetProperty and throw ...
final keyword in method parameters [duplicate]
...them to methods. This means the final doesn't mean any difference for the calling code. This only means that inside the method the variables can not be reassigned. (note that if you have a final object, you can still change the attributes of the object).
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