大约有 47,000 项符合查询结果（耗时：0.0707秒） [XML]
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 = {
...
How to find out the number of CPUs using python
...thony Sottile
33.3k99 gold badges6666 silver badges100100 bronze badges
answered Jun 17 '09 at 10:53
Nadia AlramliNadia Alramli
94...
What is “point free” style (in Functional Programming)?
...you specify the arguments explicitly):
sum (x:xs) = x + (sum xs)
sum [] = 0
Point-free (sum doesn't have any explicit arguments - it's just a fold with + starting with 0):
sum = foldr (+) 0
Or even simpler: Instead of g(x) = f(x), you could just write g = f.
So yes: It's closely related to c...
Check if a number has a decimal place/is a whole number
...
20 Answers
20
Active
...
CPU Privilege Rings: Why rings 1 and 2 aren't used?
...art of the modern protection model) only has a concept of privileged (ring 0,1,2) and unprivileged, the benefit to rings 1 and 2 were diminished greatly.
The intent by Intel in having rings 1 and 2 is for the OS to put device drivers at that level, so they are privileged, but somewhat separated fro...
How to use FormData for AJAX file upload?
...
480
For correct form data usage you need to do 2 steps.
Preparations
You can give your whole form...
Immutable vs Mutable types
...
What? Floats are immutable? But can't I do
x = 5.0
x += 7.0
print x # 12.0
Doesn't that "mut" x?
Well you agree strings are immutable right? But you can do the same thing.
s = 'foo'
s += 'bar'
print s # foobar
The value of the variable changes, but it changes by chang...
Format JavaScript date as yyyy-mm-dd
I have a date with the format Sun May 11,2014 . How can I convert it to 2014-05-11 using JavaScript?
42 Answers
...
Read a zipped file as a pandas DataFrame
...long form:
df = pd.read_csv('filename.zip', compression='zip', header=0, sep=',', quotechar='"')
Description of the compression argument from the docs:
compression : {‘infer’, ‘gzip’, ‘bz2’, ‘zip’, ‘xz’, None}, default ‘infer’
For on-the-fly decompression of on-d...
Print all day-dates between two dates [duplicate]
...
I came up with this:
from datetime import date, timedelta
sdate = date(2008, 8, 15) # start date
edate = date(2008, 9, 15) # end date
delta = edate - sdate # as timedelta
for i in range(delta.days + 1):
day = sdate + timedelta(days=i)
print(day)
The output:
2008-08-15
2008-...