大约有 7,000 项符合查询结果（耗时：0.0211秒） [XML]
Number of elements in a javascript object
...ction()
{
var i = 0;
for ( var p in this ) i++;
return i;
}
alert( {foo:"bar", bar: "baz"}.length() ); // alerts 3
But this creates problems, or at least questions. All user-created properties are counted, including the _length function itself! And while in this simple example you could a...
Git is ignoring files that aren't in gitignore
...ore only newly-added files, not ones already in the repo. So when I added "foo/" to my .gitignore, it ignored only recently added files in foo subdirectories and not all files. Took me an hour to figure out why some files were being ignored and others weren't.
– ccleve
...
ImportError: Cannot import name X
...r others. Note that if you're importing a local submodule (i.e. import app.foo.bar) you need to give it a name (i.e. import app.foo.bar as bar)
– data princess
Jul 28 at 21:48
...
Is there a standard way to list names of Python modules in a package?
... As a matter of fact, this only seems to work if I import my_package.foo and not just import mypackage, in which case it then returns foo. But this defeats the purpose
– Amelio Vazquez-Reina
Jun 26 '13 at 16:52
...
C++ Dynamic Shared Library on Linux
...terface.hpp:
class Base {
public:
virtual ~Base() {}
virtual void foo() const = 0;
};
using Base_creator_t = Base *(*)();
Shared library content:
#include "Interface.hpp"
class Derived: public Base {
public:
void foo() const override {}
};
extern "C" {
Base * create() {
return...
How to output MySQL query results in CSV format?
...to-a-text-or-csv-file/
SELECT order_id,product_name,qty
FROM orders
WHERE foo = 'bar'
INTO OUTFILE '/var/lib/mysql-files/orders.csv'
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\n';
Using this command columns names will not be exported.
Also note that /var/lib/mysql-files/order...
Is the ternary operator faster than an “if” condition in Java [duplicate]
... to use the ternary operator. If you don't have an assignment:
(i == 0) ? foo () : bar ();
an if/else isn't that much more code:
if (i == 0) foo (); else bar ();
In performance critical cases: measure it. Measure it with the target machine, the target JVM, with typical data, if there is a bot...
Sort JavaScript object by key
... by its keys/properties, alphabetically:
const unordered = {
'b': 'foo',
'c': 'bar',
'a': 'baz'
};
console.log(JSON.stringify(unordered));
// → '{"b":"foo","c":"bar","a":"baz"}'
const ordered = {};
Object.keys(unordered).sort().forEach(function(key) {
ordered[key] = unord...
Removing item from vector, while in C++11 range 'for' loop?
...y using:
for (MyVector::iterator b = v.begin(); b != v.end();) {
if (foo) {
b = v.erase( b ); // reseat iterator to a valid value post-erase
else {
++b;
}
}
Note, that you need the b != v.end() test as-is. If you try to optimize it as follows:
for (MyVector::iterator b...
Adding multiple class using ng-class
...lt;div ng-class="[class1, class2]"></div>
Usage:
<div class="foo bar" class1="foo" class2="bar"></div>
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