大约有 7,000 项符合查询结果（耗时：0.0419秒） [XML]
What does curly brackets in the `var { … } = …` statements do?
...perties from objects into distinct variables.
Eg: Array Destructuring
var foo = ["one", "two", "three"];
//without destructuring
var one = foo[0];
var two = foo[1];
var three = foo[2];
// with destructuring
var[one,two,three] = foo
Eg: Object Destructuring
var o = {p: 42, q: true};
var ...
git pull while not in a git directory
...a different directory without leaving the current directory:
(cd ~/foo && git status)
git --git-dir=~/foo/.git --work-tree=~/foo status
GIT_DIR=~/foo/.git GIT_WORK_TREE=~/foo git status
(cd ../..; git grep foo)
for d in d1 d2 d3; do (cd $d && git svn rebase); done
...
Using sed and grep/egrep to search and replace
...d separator. This is important to match the -Z of egrep and to avoid being fooled by spaces and newlines in input filenames.
-l: use one line per command as parameter
sed: the stream editor
-i: replace the input file with the output without making a backup
-e: use the following argument as expres...
How do I return multiple values from a function in C?
... Tuple getPair() {
Tuple r = { 1, getString() };
return r;
}
void foo() {
struct Tuple t = getPair();
}
2: Use pointers to pass out values.
void getPair(int* a, string* b) {
// Check that these are not pointing to NULL
assert(a);
assert(b);
*a = 1;
*b = getString(...
Curious null-coalescing operator custom implicit conversion behaviour
... analysis but before code generation -- we reduce the expression
result = Foo() ?? y;
from the example above to the moral equivalent of:
A? temp = Foo();
result = temp.HasValue ?
new int?(A.op_implicit(Foo().Value)) :
y;
Clearly that is incorrect; the correct lowering is
result = te...
Add only non-whitespace changes
...is works
git stash && git stash apply && git diff -w > foo.patch && git checkout . && git apply foo.patch && rm foo.patch
I don't like the stashes, but I have run into a bug in git + cygwin where I lose changes, so to make sure that stuff went to the ref...
Create new user in MySQL and give it full access to one database
...mysql -e "SELECT 1"
or print statement from the standard input:
$ echo "FOO STATEMENT" | mysql
If you've got Access denied with above, specify -u (for user) and -p (for password) parameters, or for long-term access set your credentials in ~/.my.cnf, e.g.
[client]
user=root
password=root
Sh...
To ternary or not to ternary? [closed]
...subconscious rules I tend to follow are:
Only evaluate 1 expression - so foo = (bar > baz) ? true : false, but NOT foo = (bar > baz && lotto && someArray.Contains(someValue)) ? true : false
If I'm using it for display logic, e.g. <%= (foo) ? "Yes" : "No" %>
Only really ...
What are C++ functors and their uses?
...function, to create functors from functions and methods, like this:
class Foo
{
public:
void operator () (int i) { printf("Foo %d", i); }
};
void Bar(int i) { printf("Bar %d", i); }
Foo foo;
boost::function<void (int)> f(foo);//wrap functor
f(1);//prints "Foo 1"
boost::function<void (i...
What is stdClass in PHP?
...eturns an StdClass instance.
<?php
//Example with StdClass
$json = '{ "foo": "bar", "number": 42 }';
$stdInstance = json_decode($json);
echo $stdInstance->foo . PHP_EOL; //"bar"
echo $stdInstance->number . PHP_EOL; //42
//Example with associative array
$array = json_decode($json, true);
ec...