大约有 12,000 项符合查询结果（耗时：0.0568秒） [XML]
How to pass a single object[] to a params object[]
...imple typecast will ensure the compiler knows what you mean in this case.
Foo((object)new object[]{ (object)"1", (object)"2" }));
As an array is a subtype of object, this all works out. Bit of an odd solution though, I'll agree.
...
How to make a class property? [duplicate]
... bar(cls, value):
cls._bar = value
# test instance instantiation
foo = Bar()
assert foo.bar == 1
baz = Bar()
assert baz.bar == 1
# test static variable
baz.bar = 5
assert foo.bar == 5
# test setting variable on the class
Bar.bar = 50
assert baz.bar == 50
assert foo.bar == 50
The sette...
PHP: How to use array_filter() to filter array keys?
... to ARRAY_FILTER_USE_KEY to filter by key instead of value:
$my_array = ['foo' => 1, 'hello' => 'world'];
$allowed = ['foo', 'bar'];
$filtered = array_filter(
$my_array,
function ($key) use ($allowed) {
return in_array($key, $allowed);
},
ARRAY_FILTER_USE_KEY
);
Cle...
How to get the return value from a thread in python?
The function foo below returns a string 'foo' . How can I get the value 'foo' which is returned from the thread's target?
...
How to randomly select an item from a list?
...
Use random.choice()
import random
foo = ['a', 'b', 'c', 'd', 'e']
print(random.choice(foo))
For cryptographically secure random choices (e.g. for generating a passphrase from a wordlist) use secrets.choice()
import secrets
foo = ['battery', 'correct', 'ho...
What is “export default” in javascript?
...n you can import that default export by omitting the curly braces:
import foo from "foo";
foo(); // hello!
Update: As of June 2015, the module system is defined in §15.2 and the export syntax in particular is defined in §15.2.3 of the ECMAScript 2015 specification.
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What is the difference between the GNU Makefile variable assignments =, ?=, := and +=?
...s evaluated when VARIABLE is accessed. It is equivalent to
ifeq ($(origin FOO), undefined)
FOO = bar
endif
See the documentation for more details.
Append
VARIABLE += value
Appending the supplied value to the existing value (or setting to that value if the variable didn't exist)
...
Set a default parameter value for a JavaScript function
...ing you want, including false or null. (typeof null == "object")
function foo(a, b) {
a = typeof a !== 'undefined' ? a : 42;
b = typeof b !== 'undefined' ? b : 'default_b';
...
}
share
|
imp...
Adding a Method to an Existing Object Instance
...here is a difference between functions and bound methods.
>>> def foo():
... print "foo"
...
>>> class A:
... def bar( self ):
... print "bar"
...
>>> a = A()
>>> foo
<function foo at 0x00A98D70>
>>> a.bar
<bound method A.bar of &...
Scala: What is a TypeTag and how do I use it?
... Scala's types are erased at runtime (type erasure). If we wanna do
class Foo
class Bar extends Foo
def meth[A](xs: List[A]) = xs match {
case _: List[String] => "list of strings"
case _: List[Foo] => "list of foos"
}
we will get warnings:
<console>:23: warning: non-variable typ...