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this.setState isn't merging states as I would expect
...construct a new state and then call setState() on that:
var newSelected = _.extend({}, this.state.selected);
newSelected.name = 'Barfoo';
this.setState({ selected: newSelected });
I've used function _.extend() function (from underscore.js library) here to prevent modification to the existing sele...
VB.NET equivalent to C# var keyword [duplicate]
...ype '<variablename>' is not defined." - and VarType(variable) is actually just the VB version of variable.GetType() which returns the type of the instance stored in the variable at runtime) I used:
Function MyVarType(Of T)(ByRef Var As T) As Type
Return GetType(T)
End Function
In detail...
How to convert a PIL Image into a numpy array?
....readthedocs.io/en/3.4.x/reference/…), but a pillow image implements the __array_interface__ which numpy can use to access the raw bytes of an image without having to pass through an iterator (see github.com/python-pillow/Pillow/blob/… and docs.scipy.org/doc/numpy/reference/arrays.interface.html...
What's the idiomatic syntax for prepending to a short python list?
... @MattM. If you insert at the front of a list, python has to move all the other items one space forwards, lists can't "make space at the front". collections.deque (double ended queue) has support for "making space at the front" and is much faster in this case.
– fejfo
...
Perform .join on value in array of objects
...Array.prototype.map is what you're looking for if you want to code functionally.
[
{name: "Joe", age: 22},
{name: "Kevin", age: 24},
{name: "Peter", age: 21}
].map(function(elem){
return elem.name;
}).join(",");
In modern JavaScript:
[
{name: "Joe", age: 22},
{name: "Kevin", age: 2...
How to unit test an object with database queries
I've heard that unit testing is "totally awesome", "really cool" and "all manner of good things" but 70% or more of my files involve database access (some read and some write) and I'm not sure how to write a unit test for these files.
...
@selector() in Swift?
... for: .touchUpInside)
view.perform(#selector(UIView.insertSubview(_:aboveSubview:)),
with: button, with: otherButton)
The great thing about this approach? A function reference is checked by the Swift compiler, so you can use the #selector expression only with class/method pair...
In a javascript array, how do I get the last 5 elements, excluding the first element?
... huge javascript minified file if your trying to do it from your browser.
_.slice(_.rest(arr), -5)
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How can I programmatically determine if my app is running in the iphone simulator?
...er "Compiling source code conditionally"
The relevant definition is TARGET_OS_SIMULATOR, which is defined in /usr/include/TargetConditionals.h within the iOS framework. On earlier versions of the toolchain, you had to write:
#include "TargetConditionals.h"
but this is no longer necessary on the ...
Performance of foreach, array_map with lambda and array_map with static function
...
}
return $result;
}
function useMapClosure($numbers) {
return array_map(function($number) {
return $number * 10;
}, $numbers);
}
function _tenTimes($number) {
return $number * 10;
}
function useMapNamed($numbers) {
return array_map('_tenTimes', $numbers);
}
foreach (array('F...