大约有 40,000 项符合查询结果（耗时：0.0636秒） [XML]
What belongs in an educational tool to demonstrate the unwarranted assumptions people make in C/C++?
...Z80
We like to think that:
..09a minus shifts backwards
but '(t=-1,(15<<t)==7)' is false.
..19-2 short<int
but 'sizeof(short)<sizeof(int)' is false.
..22 floating point is always IEEE
but 'STDC_IEC_559_is_defined' is false.
..25 pointer arithmetic works outside arrays
but '(...
Find and restore a deleted file in a Git repository
...HEAD commit, this commit must have deleted it.
git rev-list -n 1 HEAD -- <file_path>
Then checkout the version at the commit before, using the caret (^) symbol:
git checkout <deleting_commit>^ -- <file_path>
Or in one command, if $file is the file in question.
git checkout $...
Difference between except: and except Exception as e: in Python
...args
...
>>> catch()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 3, in catch
BaseException
Which a bare except does:
>>> def catch():
... try:
... raise BaseException()
... except:
... ...
$(window).width() not the same as media query
I am using Twitter Bootstrap on a project. As well as the default bootstrap styles I have also added some of my own
17 Ans...
“’” showing on page instead of “ ' ”
...display the characters.
I have the Content-Type set to UTF-8 in both my <head> tag and my HTTP headers:
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
This only instructs the client which encoding to use to interpret and display the characters. This doesn't ins...
How to printf uint64_t? Fails with: “spurious trailing ‘%’ in format”
...e defined if explicitly requested.
#define __STDC_FORMAT_MACROS
#include <inttypes.h>
... now PRIu64 will work
share
|
improve this answer
|
follow
|
...
Omit rows containing specific column of NA
...ld use the complete.cases function and put it into a function thusly:
DF <- data.frame(x = c(1, 2, 3), y = c(0, 10, NA), z=c(NA, 33, 22))
completeFun <- function(data, desiredCols) {
completeVec <- complete.cases(data[, desiredCols])
return(data[completeVec, ])
}
completeFun(DF, "y")...
Why do I get a warning every time I use malloc?
...
You need to add:
#include <stdlib.h>
This file includes the declaration for the built-in function malloc. If you don't do that, the compiler thinks you want to define your own function named malloc and it warns you because:
You don't explicit...
Meaning of 'const' last in a function declaration of a class?
...e which is called when the object is const, and one that isn't.
#include <iostream>
class MyClass
{
private:
int counter;
public:
void Foo()
{
std::cout << "Foo" << std::endl;
}
void Foo() const
{
std::cout << "Foo const" <&l...
Why do C and C++ compilers allow array lengths in function signatures when they're never enforced?
...1 As a C programmer, I find this answer incorrect. [] are not ignored in multidimensional arrays as shown in pat's answer. So including array syntax was necessary. In addition, nothing stops compiler from issuing warnings even on single dimensional arrays.
– user694733
...