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Getting a better understanding of callback functions in JavaScript
...epending how you call the function
alert(this);
};
callback(argument_1, argument_2);
callback.call(some_object, argument_1, argument_2);
callback.apply(some_object, [argument_1, argument_2]);
The method you choose depends whether:
You have the arguments stored in an Array or as distinct v...
How do I declare an array of weak references in Swift?
...T] {
return objects.flatMap { $0.object }
}
func contains(_ object: T) -> Bool {
return self.objects.contains(WeakObject(object: object))
}
func addObject(_ object: T) {
self.objects.formUnion([WeakObject(object: object)])
}
func addObjects(_ obj...
数据存储组件 · App Inventor 2 中文网
...AI伴侣的App目录，如果最终编译apk运行，则到 appinventor.ai_[账户名].[项目名] 目录下查看文件）
写入文件的参考代码如下：
生成的文件如下：
程序包 ：从应用程序包...
How to get the name of the calling method?
...eem to work in Rails 5.2.1. In Rails controller this returns "block in make_lambda". I guess this is for Ruby only.
– dcangulo
Nov 14 '18 at 4:59
add a comment
...
How do I output coloured text to a Linux terminal?
...f the escape sequence for ANSI color codes. Ref: en.wikipedia.org/wiki/ANSI_escape_code#CSI_codes
– thameera
Sep 22 '14 at 8:27
21
...
Standardize data columns in R
...
z = runif(10, 10, 20))
dat
dat2 <- dat %>% mutate_at(c("y", "z"), ~(scale(.) %>% as.vector))
dat2
which gives me this:
> dat
x y z
1 29.75859 3.633225 14.56091
2 30.05549 3.605387 12.65187
3 30.21689 3.318092 13.04672
4 29.53086 3.079992...
Android AsyncTask testing with Android Test Framework
... runTestOnUiThread():
public final void testExecute() {
startActivity(_startIntent, null, null);
runTestOnUiThread(new Runnable() {
public void run() {
Button btnStart = (Button) getActivity().findViewById(R.id.Button01);
btnStart.performClick();
}
...
How do Python's any and all functions work?
... entire iterable need not be consumed. For example,
>>> multiples_of_6 = (not (i % 6) for i in range(1, 10))
>>> any(multiples_of_6)
True
>>> list(multiples_of_6)
[False, False, False]
Here, (not (i % 6) for i in range(1, 10)) is a generator expression which returns Tru...
specify project file of a solution using msbuild
...ains any of the characters %, $, @, ;, ., (, ), or ', replace them with an _ in the specified target name.
You can also build multiple projects at once:
msbuild test.sln /t:project;project2 /p:Configuration="Release" /p:Platform="x86" /p:BuildProjectReferences=false
To rebuild or clean, change ...
PHP method chaining?
...turned object.
<?php
class fakeString
{
private $str;
function __construct()
{
$this->str = "";
}
function addA()
{
$this->str .= "a";
return $this;
}
function addB()
{
$this->str .= "b";
return $this;
}
...