大约有 30,000 项符合查询结果（耗时：0.0341秒） [XML]
How to get the text node of an element?
... possible iterations. Comparing two small numbers is better than comparing strings of various lengths (time and space considerations). The correct question to ask in this situation is "what kind / type of node do I have?", and not "what name do I have?" developer.mozilla.org/en-US/docs/Web/API/Node/...
iPhone get SSID without private library
...s: %@", __func__, interfaceNames);
NSDictionary *SSIDInfo;
for (NSString *interfaceName in interfaceNames) {
SSIDInfo = CFBridgingRelease(
CNCopyCurrentNetworkInfo((__bridge CFStringRef)interfaceName));
NSLog(@"%s: %@ => %@", __func__, interfaceName, SSIDInfo)...
Are there any downsides to passing structs by value in C, rather than passing a pointer?
...e output parameters be listed first before input parameters, e.g. int func(char* out, char *in);
– zooropa
Apr 29 '09 at 12:29
...
Simple logical operators in Bash
... a variable is empty and -e $file to test if a file exists. There are also string equality operators: "$string1" == "$string2" (beware that the right-hand side is a pattern, e.g. [[ $foo == a* ]] tests if $foo starts with a while [[ $foo == "a*" ]] tests if $foo is exactly a*), and the familiar !, &...
Concatenate multiple result rows of one column into one, group by another column [duplicate]
...
Simpler with the aggregate function string_agg() (Postgres 9.0 or later):
SELECT movie, string_agg(actor, ', ') AS actor_list
FROM tbl
GROUP BY 1;
The 1 in GROUP BY 1 is a positional reference and a shortcut for GROUP BY movie in this case.
string_agg() ...
How do you print out a stack trace to the console/log in Cocoa?
...#import <UIKit/UIKit.h>
#import "AppDelegate.h"
int main(int argc, char *argv[])
{
@autoreleasepool {
int retval;
@try{
retval = UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
}
@catch (NSException *exception)
...
Does delete on a pointer to a subclass call the base class destructor?
...n this will happen when the containing object is destroyed.
class A
{
char *someHeapMemory;
public:
A() : someHeapMemory(new char[1000]) {}
~A() { delete[] someHeapMemory; }
};
class B
{
A* APtr;
public:
B() : APtr(new A()) {}
~B() { delete APtr; }
};
class C
{
A Amemb...
HTML5 form required attribute. Set custom validation message?
...ly answered. If setCustomValidity is set to anything other than the empty string it will cause the field to be considered invalid; therefore you must clear it before testing validity, you can't just set it and forget.
Further edit
As pointed out in @thomasvdb's comment below, you need to clear the ...
Difference between a Structure and a Union
...re that value.
union foo {
int a; // can't use both a and b at once
char b;
} foo;
struct bar {
int a; // can use both a and b simultaneously
char b;
} bar;
union foo x;
x.a = 3; // OK
x.b = 'c'; // NO! this affects the value of x.a!
struct bar y;
y.a = 3; // OK
y.b = 'c'; // OK
ed...
Do I need to disable NSLog before release Application?
...BUG_MODE
#define DLog( s, ... ) NSLog( @"<%p %@:(%d)> %@", self, [[NSString stringWithUTF8String:__FILE__] lastPathComponent], __LINE__, [NSString stringWithFormat:(s), ##__VA_ARGS__] )
#else
#define DLog( s, ... )
#endif
Now instead of NSLog use DLog everywhere. When testing and debugging...