大约有 40,000 项符合查询结果（耗时：0.0442秒） [XML]
mongodb group values by multiple fields
...tems to $push to an array.
db.books.aggregate([
{ "$group": {
"_id": {
"addr": "$addr",
"book": "$book"
},
"bookCount": { "$sum": 1 }
}},
{ "$group": {
"_id": "$_id.addr",
"books": {
"$push": {
...
How do I detect a click outside an element?
...')
.find('a:first')
.focus();
e.preventDefault();
}
$('.menu__link').on({
click: function (e) {
$(this.hash)
.toggleClass('submenu--active')
.find('a:first')
.focus();
e.preventDefault();
},
focusout: function () {
$(this.hash).data('submenuTimer', ...
Python, creating objects
... ""
# The class "constructor" - It's actually an initializer
def __init__(self, name, age, major):
self.name = name
self.age = age
self.major = major
def make_student(name, age, major):
student = Student(name, age, major)
return student
Note that even tho...
Header files for x86 SIMD intrinsics
.../x86-64 use x86intrin.h
For gcc/clang/armcc targeting ARM with NEON use arm_neon.h
For gcc/clang/armcc targeting ARM with WMMX use mmintrin.h
For gcc/clang/xlcc targeting PowerPC with VMX (aka Altivec) and/or VSX use altivec.h
For gcc/clang targeting PowerPC with SPE use spe.h
You can handle all t...
PHP function overloading
...c function that takes in a variable number of arguments. You would use func_num_args() and func_get_arg() to get the arguments passed, and use them normally.
For example:
function myFunc() {
for ($i = 0; $i < func_num_args(); $i++) {
printf("Argument %d: %s\n", $i, func_get_arg($i))...
How to work with complex numbers in C?
...a standard c99 type (under the hood on GCC, it is actually an alias to the _Complex type).
– Snaipe
Apr 12 '15 at 8:50
...
STL：accumulate与自定义数据类型 - C/C++ - 清泛网 - 专注C/C++及内核技术
...mulate()的原型为(文件取自DEV-C++编译器)：
template<typename _InputIterator, typename _Tp, typename _BinaryOperation>
_Tp accumulate(_InputIterator __first, _InputIterator __last, _Tp __init,
_BinaryOperation __binary_op)
{
// concept requirements
__glibcxx...
What does “#define _GNU_SOURCE” imply?
...
Defining _GNU_SOURCE has nothing to do with license and everything to do with writing (non-)portable code. If you define _GNU_SOURCE, you will get:
access to lots of nonstandard GNU/Linux extension functions
access to traditional fu...
BaseException.message deprecated in Python 2.6
...s that only a
single string argument be passed to the constructor."""
__str__ and __repr__ are already implemented in a meaningful way,
especially for the case of only one arg (that can be used as message).
You do not need to repeat __str__ or __init__ implementation or create _get_message as s...
Append text to input field
...might want to write a function:
//Append text to input element
function jQ_append(id_of_input, text){
var input_id = '#'+id_of_input;
$(input_id).val($(input_id).val() + text);
}
After you can just call it:
jQ_append('my_input_id', 'add this text');
...