大约有 40,000 项符合查询结果（耗时：0.0503秒） [XML]
Check if an array is empty or exists
...y" !== "array"
typeof array == "undefined"; // => true
Case Null
Generally speaking, null is state of lacking a value. For example a variable is null when you missed or failed to retrieve some data.
array = searchData(); // can't find anything
array == null; // => true
Case Not a...
Setting Django up to use MySQL
...ine, you can use
python manage.py runserver
Adding the ip:port argument allows machines other than your own to access your development application. Once you are ready to deploy your application, I recommend taking a look at the chapter on Deploying Django on the djangobook
Mysql default characte...
How can I find an element by CSS class with XPath?
.../div[contains(concat(' ', @class, ' '), ' Test ')]
If you wished to be really certain that it will match correctly, you could also use the normalize-space function to clean up stray whitespace characters around the class name (as mentioned by @Terry):
//div[contains(concat(' ', normalize-space(@...
Styling HTML email for Gmail
...
}
</style>
<xml>
<o:OfficeDocumentSettings>
<o:AllowPNG/>
<o:PixelsPerInch>96</o:PixelsPerInch>
</o:OfficeDocumentSettings>
</xml>
<![endif]-->
This is just a simple example, but, who know, it might come in handy some time.
...
getMinutes() 0-9 - How to display two digit numbers?
...
(condition?true:false) in PHP you can omit the true statement (condition?:false) in JS you would then use (condition||false) Ternary operator en.wikipedia.org/wiki/Ternary_operation
– llange
Mar 16 '19 at 9:53
...
git add all except ignoring files in .gitignore file
...roject that had none. The problem is that there are a lot of files to initially add to git with a .gitignore file, but I can't figure out how to add all files without including the files matching something in the .gitignore file.
...
Breaking out of a nested loop
...using goto is any worse than the normal use of something like break (after all they're both just unconditional branches to a label, it's just that with break the label is implicit).
– Greg Beech
Nov 28 '08 at 0:07
...
How to compare two floating point numbers in Bash?
...true or false.
Please, ensure that the bc basic calculator package is installed.
This equally works for floats in scientific format, provided a capital letter E is employed, e.g. num1=3.44E6
share
|
...
What online brokers offer APIs? [closed]
So I'm getting really sick of E*TRADE and, being a developer, would love to find an online broker that offers an API. It would be great to be able to write my own trading tools, and maybe even modify existing ones.
...
Tetris-ing an array
...a include the algorithm to find the longest common prefix, thus making actually using a tree structure unnecessary? Ie why check the tree for multiple children when you could detect that while building the tree. Why then a tree at all? I mean if you start with an array already. If you can change the...