大约有 40,000 项符合查询结果（耗时：0.0501秒） [XML]
How to check for an undefined or null variable in JavaScript?
...n converted to a boolean, evaluates to false. So, if you don't care about
0 and false, using if(obj.undefProp) is ok. There's a common idiom based on this fact:
value = obj.prop || defaultValue
which means "if obj has the property prop, assign it to value, otherwise assign the default value defa...
Using ls to list directories and their total sizes
...
1607
Try something like:
du -sh *
short version of:
du --summarize --human-readable *
Explanat...
Integer to hex string in C++
...esult( stream.str() );
You can prepend the first << with << "0x" or whatever you like if you wish.
Other manips of interest are std::oct (octal) and std::dec (back to decimal).
One problem you may encounter is the fact that this produces the exact amount of digits needed to represent...
Regular Expression to reformat a US phone number in Javascript
...
Assuming you want the format "(123) 456-7890":
function formatPhoneNumber(phoneNumberString) {
var cleaned = ('' + phoneNumberString).replace(/\D/g, '')
var match = cleaned.match(/^(\d{3})(\d{3})(\d{4})$/)
if (match) {
return '(' + match[1] + ') ' + match[2...
mysqldump - Export structure only without autoincrement
...t; --opt <db-name> -d --single-transaction | sed 's/ AUTO_INCREMENT=[0-9]*\b//' > <filename>.sql
As mentioned by others, If you want sed to works properly, add the g (for global replacement) parameter like this :
mysqldump -u root -p -h <db-host> --opt <db-name> -d --s...
Generate pdf from HTML in div using Javascript
...urn true;
}
};
var source = window.document.getElementsByTagName("body")[0];
doc.fromHTML(
source,
15,
15,
{
'width': 180,'elementHandlers': elementHandler
});
doc.output("dataurlnewwindow");
For me this created a nice and tidy PDF that only included the line 'print th...
MYSQL OR vs IN performance
...ir "opinion", science is all about testing and evidence.
I ran a loop of 1000x the equivalent queries (for consistency, I used sql_no_cache):
IN: 2.34969592094s
OR: 5.83781504631s
Update:
(I don't have the source code for the original test, as it was 6 years ago, though it returns a result in th...
Is it possible to change a UIButtons background color?
...
160
This can be done programmatically by making a replica:
loginButton = [UIButton buttonWithType:U...
Maven Could not resolve dependencies, artifacts could not be resolved
...|
edited Sep 4 '19 at 22:10
answered Jan 10 '11 at 19:13
wm...
How to check if remote branch exists on a given remote repository?
...ame
In case branch-name is found you will get the following output:
b523c9000c4df1afbd8371324083fef218669108 refs/heads/branch-name
Otherwise no output will be sent.
So piping it to wc will give you 1 or 0:
$ git ls-remote --heads git@github.com:user/repo.git branch-name | wc -l
Alternativ...