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Why are all fields in an interface implicitly static and final?
I am just trying to understand why all fields defined in an Interface are implicitly static and final . The idea of keeping fields static makes sense to me as you can't have objects of an interface but why they are final (implicitly)?
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JavaScript Regular Expression Email Validation [duplicate]
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If you define your regular expression as a string then all backslashes need to be escaped, so instead of '\w' you should have '\\w'.
Alternatively, define it as a regular expression:
var pattern = /^\w+@[a-zA-Z_]+?\.[a-zA-Z]{2,3}$/;
BTW, please don't validate email address...
Pandas selecting by label sometimes return Series, sometimes returns DataFrame
...answered Dec 4 '13 at 19:36
Dan AllanDan Allan
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计算统计特征（正态分布）函数及实例 - C/C++ - 清泛网 - 专注C/C++及内核技术
...AX_VAR;
double _ave;
//double _var;
double _sam_stdev;
double _all_stdev;
double _sum;
double _sum_2;
int _count;
double _min_v;
double _max_v;
StdevInfo()
: _ave(0.0)
//, _var(MAX_VAR)
, _sam_stdev(sqrt(MAX_VAR))
, _all_stdev(0.0)
, _sum(0.0)
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How do I clear only a few specific objects from the workspace?
I would like to remove some data from the workspace. I know the "Clear All" button will remove all data. However, I would like to remove just certain data.
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One-liner to check whether an iterator yields at least one element?
... Similarly if you need to check if the iterator is empty, one could use all(False for _ in iterator) will check if the iterator is empty. (all returns True if the iterator is empty, otherwise it stops when it sees the first False element)
– KGardevoir
Apr 3 ...
What is the purpose of the single underscore “_” variable in Python?
...cate that part
of a function result is being deliberately ignored (Conceptually, it is being discarded.), as in code like:
label, has_label, _ = text.partition(':').
As part of a function definition (using either def or lambda), where
the signature is fixed (e.g. by a callback or parent class API), ...
detach all packages while working in R
...*) is not necessary but can be useful to prevent the NULL reply from vertically spamming the R window.
(edit: 9/20/2019) In version 3.6.1
It may be helpful to convert loaded only names(sessionInfo()$loadedOnly) to explicitly attached packages first, and then detach the packages, as so.
lapply(names(...
Is there any way to kill a Thread?
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It is generally a bad pattern to kill a thread abruptly, in Python and in any language. Think of the following cases:
the thread is holding a critical resource that must be closed properly
the thread has created several other threads ...
mongodb/mongoose findMany - find all documents with IDs listed in array
I have an array of _ids and I want to get all docs accordingly, what's the best way to do it ?
5 Answers
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