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php中json_decode()和json_encode()的使用方法 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...de()和json_encode()的使用方法1.json_decode()json_decode(PHP 5 >= 5.2.0, PECL json >= 1.2.0)json_decode — 对 JSON 格式的字符串进行编码说明mixed jso...1.json_decode()
(PHP 5 >= 5.2.0, PECL json >= 1.2.0)
对 JSON 格式的字符串进行编码
说明：
mixed json_decode ...
Replace a value if null or undefined in JavaScript
...
Here’s the JavaScript equivalent:
var i = null;
var j = i || 10; //j is now 10
Note that the logical operator || does not return a boolean value but the first value that can be converted to true.
Additionally use an array of objects instead of one single object:
var options = {
...
Pandas get topmost n records within each group
...
>>> df.groupby('id').head(2)
id value
id
1 0 1 1
1 1 2
2 3 2 1
4 2 2
3 7 3 1
4 8 4 1
(Keep in mind that you might need to order/sort before, depending on your data)
EDIT: As mentioned by the questioner, use df.gro...
Numpy how to iterate over columns of array?
...
– Ibrahim Muhammad
Sep 23 '13 at 17:08
49
For those wondering, array.T isn't costly, as it just c...
How do I install the OpenSSL libraries on Ubuntu?
I'm trying to build some code on Ubuntu 10.04 LTS that uses OpenSSL 1.0.0. When I run make, it invokes g++ with the "-lssl" option. The source includes:
...
Find the extension of a filename in Ruby
...
That's really basic stuff:
irb(main):002:0> accepted_formats = [".txt", ".pdf"]
=> [".txt", ".pdf"]
irb(main):003:0> File.extname("example.pdf") # get the extension
=> ".pdf"
irb(main):004:0> accepted_formats.include? File.extname("example.pdf")
=...
Clear icon inside input text
...ch" to your input
The support is pretty decent but will not work in IE<10
<input type="search">
Clearable input for old browsers
If you need IE9 support here are some workarounds
Using a standard <input type="text"> and some HTML elements:
/**
* Clearable text ...
JavaScript + Unicode regexes
...
205
Situation for ES 6
The upcoming ECMAScript language specification, edition 6, includes Unicode-...
What is the Ruby (spaceship) operator?
...ther language that supports it. Basically instead of returning 1 (true) or 0 (false) depending on whether the arguments are equal or unequal, the spaceship operator will return 1, 0, or −1 depending on the value of the left argument relative to the right argument.
a <=> b :=
if a < b t...
How do I calculate a point on a circle’s circumference?
...
600
The parametric equation for a circle is
x = cx + r * cos(a)
y = cy + r * sin(a)
Where r is t...