大约有 43,000 项符合查询结果(耗时:0.0610秒) [XML]
Catching error codes in a shell pipe
...
If you really don't want the second command to proceed until the first is known to be successful, then you probably need to use temporary files. The simple version of that is:
tmp=${TMPDIR:-/tmp}/mine.$$
if ./a > $tmp.1
then
if ./b <$tmp.1 >$tmp.2
...
SQL “select where not in subquery” returns no results
...emantically the same.
When it is nullable, NOT IN is different, since IN (and, therefore, NOT IN) return NULL when a value does not match anything in a list containing a NULL.
This may be confusing but may become more obvious if we recall the alternate syntax for this:
common_id = ANY
(
SELECT c...
JavaScript property access: dot notation vs. brackets?
Other than the obvious fact that the first form could use a variable and not just a string literal, is there any reason to use one over the other, and if so under which cases?
...
iOS - Build fails with CocoaPods cannot find header files
... on the same project. He made some changes (only to code as far as I know) and made a new branch in the repo. I have checked out his branch and tried to build it, but I am getting an error: ASLogger/ASLogger.h file not found.
...
Calculate last day of month in JavaScript
...efox 2.0.0.17: Thu Jan 31 2008 00:00:00 GMT-0600 (Canada Central Standard Time)
Firefox 3.0.3: Thu Jan 31 2008 00:00:00 GMT-0600 (Canada Central Standard Time)
Google Chrome 0.2.149.30: Thu Jan 31 2008 00:00:00 GMT-0600 (Canada Central Standard Time)
Safari for Windows 3.1.2: Thu ...
Static variables in JavaScript
...);
staticProperty is defined in the MyClass object (which is a function) and has nothing to do with its created instances, JavaScript treats functions as first-class objects, so being an object, you can assign properties to a function.
UPDATE: ES6 introduced the ability to declare classes through...
jQuery ajax error function
...
The required parameters in an Ajax error function are jqXHR, exception and you can use it like below:
$.ajax({
url: 'some_unknown_page.html',
success: function (response) {
$('#post').html(response.responseText);
},
error: function (jqXHR, exception) {
var msg = ...
What's the best way to set a single pixel in an HTML5 canvas?
...
There are two best contenders:
Create a 1×1 image data, set the color, and putImageData at the location:
var id = myContext.createImageData(1,1); // only do this once per page
var d = id.data; // only do this once per page
d[0] = r;
d[1] = g;
d[2] = b;
d[3] = a;
...
Looping through a hash, or using an array in PowerShell
...
Christian's answer works well and shows how you can loop through each hash table item using the GetEnumerator method. You can also loop through using the keys property. Here is an example how:
$hash = @{
a = 1
b = 2
c = 3
}
$hash.Keys | % { "...
Delete Local Folder in TFS
...o delete my local copy. The problem is that TFS wants to mirror the change and delete the folder from source control, I don't want to remove it from TFS.
...
