大约有 41,000 项符合查询结果（耗时：0.0520秒） [XML]
What is the maximum length of latitude and longitude? [closed]
...12.3456789), longitude 10 (123.4567890), they both have maximum 7 decimals chars (At least is what i can find in Google Maps),
For example, both columns in Rails and Postgresql looks something like this:
t.decimal :latitude, precision: 9, scale: 7
t.decimal :longitude, precision: 10, scale: 7
...
Format date and time in a Windows batch script
...ces with zeros.
Short explanation of how substrings work:
%VARIABLE:~num_chars_to_skip,num_chars_to_keep%
So to get just the year from a date like "29.03.2018" use:
%DATE:~6,4%
^-----skip 6 characters
^---keep 4 characters
...
How do you compare structs for equality in C?
...use memcmp to compare structs for equality due to potential random padding characters between field in structs.
// bad
memcmp(&struct1, &struct2, sizeof(struct1));
The above would fail for a struct like this:
typedef struct Foo {
char a;
/* padding */
double d;
/* padding */
...
Build a Basic Python Iterator
...n (defines __getitem__)
Examples:
# generator
def uc_gen(text):
for char in text.upper():
yield char
# generator expression
def uc_genexp(text):
return (char for char in text.upper())
# iterator protocol
class uc_iter():
def __init__(self, text):
self.text = text.upp...
Get the current time in C
... by now, but you would use the strptime function in time.h to convert from char * to struct tm
– KingRadical
Nov 5 '13 at 19:59
...
What is the curiously recurring template pattern (CRTP)?
...ter
{
public:
Writer() { }
~Writer() { }
void write(const char* str) const
{
static_cast<const T*>(this)->writeImpl(str); //here the magic is!!!
}
};
class FileWriter : public Writer<FileWriter>
{
public:
FileWriter(FILE* aFile) { mFile = aFile; ...
iOS Detect 3G or WiFi
...
I made a pretty simple block based Reachability wrapper that strips all the outdated C-like Reachability code, poured into a much more Cocoa form.
Usage like:
[EPPZReachability reachHost:hostNameOrIPaddress
completition:^(EPPZReachability *reachability)
{
if (reachabi...
Extract digits from a string in Java
...t probably faster:
public static String stripNonDigits(
final CharSequence input /* inspired by seh's comment */){
final StringBuilder sb = new StringBuilder(
input.length() /* also inspired by seh's comment */);
for(int i = 0; i < input.length(); i++){
fi...
Using varchar(MAX) vs TEXT on SQL Server
...es ('b')
insert into @table values ('c')
insert into @table values ('d')
select *
from @table
where a ='a'
This give an error:
The data types text and varchar are incompatible in the equal to operator.
Wheras this does not:
declare @table table (a varchar(max))
Interestingly, LIKE still wo...
Proper MIME media type for PDF files
.... This is the same organization that manages the root name servers and the IP address space.
The use of x-pdf predates the standardization of the MIME type for PDF. MIME types in the x- namespace are considered experimental, just as those in the vnd. namespace are considered vendor-specific. x-pdf ...