大约有 44,000 项符合查询结果（耗时：0.0252秒） [XML]
What is the difference between a field and a property?
...It is private to your class and stores the actual data.
private string _myField;
// this is a property. When accessed it uses the underlying field,
// but only exposes the contract, which will not be affected by the underlying field
public string MyProperty
{
get
...
ARC and bridged cast
...ription is confusing. Since I just grasped them, I'll try to summarize:
(__bridge_transfer <NSType>) op or alternatively CFBridgingRelease(op) is used to consume a retain-count of a CFTypeRef while transferring it over to ARC. This could also be represented by id someObj = (__bridge <NSTy...
How to list imported modules?
...ems():
if isinstance(val, types.ModuleType):
yield val.__name__
This won't return local imports, or non-module imports like from x import y. Note that this returns val.__name__ so you get the original module name if you used import module as alias; yield name instead if you wa...
How to check if a python module exists without importing it
...mport can find something in python2, using imp
import imp
try:
imp.find_module('eggs')
found = True
except ImportError:
found = False
To find dotted imports, you need to do more:
import imp
try:
spam_info = imp.find_module('spam')
spam = imp.load_module('spam', *spam_info)
i...
How can I output leading zeros in Ruby?
...counter is known (e.g., n = 3 for counters 1..876), you can do
str = "file_" + i.to_s.rjust(n, "0")
share
|
improve this answer
|
follow
|
...
When to use Comparable and Comparator
... | Comparable | Comparator
._______________________________________________________________________________
Is used to allow Collections.sort to work | yes | yes
Can compare multiple fields | yes ...
How to initialize a private static const map in C++?
...ap>
using namespace std;
struct A{
static map<int,int> create_map()
{
map<int,int> m;
m[1] = 2;
m[3] = 4;
m[5] = 6;
return m;
}
static const map<int,int> myMap;
};
const map<int,int> A:: myMap = ...
Nested classes' scope?
...
class Outer(object):
outer_var = 1
class Inner(object):
@property
def inner_var(self):
return Outer.outer_var
This isn't quite the same as similar things work in other languages, and uses global lookup instead of sco...
Try catch statements in C
...ou can simulate them to a degree with setjmp and longjmp calls.
static jmp_buf s_jumpBuffer;
void Example() {
if (setjmp(s_jumpBuffer)) {
// The longjmp was executed and returned control here
printf("Exception happened here\n");
} else {
// Normal code execution starts here
Te...
Bash continuation lines
...here document. (Line terminators will still remain, though.)
cat <<-____HERE
continuation
lines
____HERE
See also http://ss64.com/bash/syntax-here.html
If you need to preserve some, but not all, leading whitespace, you might use something like
sed 's/^ //' <<____HERE
Th...