大约有 2,220 项符合查询结果(耗时:0.0430秒) [XML]
What is Normalisation (or Normalization)?
...ase that usually contains family members
id, name, address
214 Mr. Chris 123 Main St.
317 Mrs. Chris 123 Main St.
could be normalized as
id name familyID
214 Mr. Chris 27
317 Mrs. Chris 27
and a family table
ID, address
27 123 Main St.
Near-Complete normalization (BCNF) is usually not used...
what is faster: in_array or isset? [closed]
...e, you can check out the compiled version of your script:
echo isset($arr[123])
compiled vars: !0 = $arr
line # * op fetch ext return operands
-----------------------------------------------------------------------------
1 0 > ZEND_ISSET_ISEMPTY_...
PHP convert XML to JSON
...ult in key pointing to array of elements: <list><item><a>123</a><a>456</a></item><item><a>123</a></item></list> -> {"item":[{"a":["123","456"]},{"a":"123"}]}. A solution at php.net by ratfactor solves that issue by always sto...
What is “export default” in javascript?
...ello() {
console.log("Modul: Saying hello!");
}
export let variable = 123;
modul2.js
export function hello2() {
console.log("Module2: Saying hello for the second time!");
}
export let variable2 = 456;
modul3.js
export default function hello3() {
console.log("Module3: Saying hello...
How can I check if a string represents an int, without using try/except?
...xcept ValueError:
return False
>>> print RepresentsInt("+123")
True
>>> print RepresentsInt("10.0")
False
It's going to be WAY more code to exactly cover all the strings that Python considers integers. I say just be pythonic on this one.
...
How to store a dataframe using Pandas
...
Pickle works good!
import pandas as pd
df.to_pickle('123.pkl') #to save the dataframe, df to 123.pkl
df1 = pd.read_pickle('123.pkl') #to load 123.pkl back to the dataframe df
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...
Getting parts of a URL (Regex)
...ex:
var a = document.createElement('a');
a.href = 'http://www.example.com:123/foo/bar.html?fox=trot#foo';
['href','protocol','host','hostname','port','pathname','search','hash'].forEach(function(k) {
console.log(k+':', a[k]);
});
/*//Output:
href: http://www.example.com:123/foo/bar.html?fox=t...
Preferred order of writing latitude & longitude tuples in GIS services
.... For example, my hometown of Eugene, Oregon is at approximately N 44.1, W 123.1. If in maps.google.com I enter 44.1 -123.1, it goes to Eugene. If I enter -123.1 44, it tells me it can't find it. Interestingly, though, if I enter 123.1 W 44 N, it figures it out and goes to Eugene, so there is some f...
Does “\d” in regex mean a digit?
I found that in 123 , \d matches 1 and 3 but not 2 . I was wondering if \d matches a digit satisfying what kind of requirement? I am talking about Python style regex.
...
Why is it Valid to Concatenate Null Strings but not to Call “null.ToString()”?
...
The first sample will be translated into:
var bob = String.Concat("abc123", null, null, null, "abs123");
The Concat method checks input and translate null as an empty string
The second sample will be translated into:
var wtf = ((object)null).ToString();
So a null reference exception will ...