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JavaScript: How to pass object by value?
...y may be to set o as the prototype of a new object.
var o = {};
(function(x){
var obj = Object.create( x );
obj.foo = 'foo';
obj.bar = 'bar';
})(o);
alert( o.foo ); // undefined
So any properties you add to obj will be not be added to o. Any properties added to obj with the same prop...
What is your favorite C programming trick? [closed]
For example, I recently came across this in the linux kernel:
37 Answers
37
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Reverse Range in Swift
...gh:1,by:-1) { print(i) } // 5 4 3 2 1
stide(from:to:by:) is similar but excludes the last value
for i in stride(from:5,to:0,by:-1) { print(i) } // 5 4 3 2 1
Update For latest Swift 2
First of all, protocol extensions change how reverse is used:
for i in (1...5).reverse() { print(i) } // 5 4 3...
Apply a function to every row of a matrix or a data frame
Suppose I have a n by 2 matrix and a function that takes a 2-vector as one of its arguments. I would like to apply the function to each row of the matrix and get a n-vector. How to do this in R?
...
Python idiom to return first item or None
...
Python 2.6+
next(iter(your_list), None)
If your_list can be None:
next(iter(your_list or []), None)
Python 2.4
def get_first(iterable, default=None):
if iterable:
for item in iterable:
return item
return d...
How to check if variable's type matches Type stored in a variable
...ns.
The is operator does not check if the runtime type of the operand is exactly the given type; rather, it checks to see if the runtime type is compatible with the given type:
class Animal {}
class Tiger : Animal {}
...
object x = new Tiger();
bool b1 = x is Tiger; // true
bool b2 = x is Animal; ...
Why are C# 3.0 object initializer constructor parentheses optional?
It seems that the C# 3.0 object initializer syntax allows one to exclude the open/close pair of parentheses in the constructor when there is a parameterless constructor existing. Example:
...
ASP.NET MVC 3: Override “name” attribute with TextBoxFor
Is it possible when using Html.TextBoxFor to override the name attribute?
11 Answers
...
Using custom std::set comparator
...ying to change the default order of the items in a set of integers to be lexicographic instead of numeric, and I can't get the following to compile with g++:
...
Make a negative number positive
...
Just call Math.abs. For example:
int x = Math.abs(-5);
Which will set x to 5.
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