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...存cache中放好可秒杀的数量，还可以把数据分布开来放，100商品，10台服务器一台放10个，无需在当时操作任何数据库。可以订单数够后，停止秒杀，然后批量写数据库。而且秒杀的商品不多。火车票这个不是像秒杀那么简单的，...
My attempt at value initialization is interpreted as a function declaration, and why doesn't A a(())
...classes which takes two arguments is std::string
std::string hundred_dots(100, '.');
This is all well and fine (technically, it would have most vexing parse if it would be written as std::string wat(int(), char()), but let's be honest - who would write that? But let's assume this code has a vexin...
How to find the length of a string in R
... uq max neval
nchar(x) 11.868 12.776 13.1590 13.6475 41.815 100
str_length(x) 30.715 33.159 33.6825 34.1360 173.400 100
stri_length(x) 2.653 3.281 4.0495 4.5380 19.966 100
and also works fine with NA's
nchar(NA)
## [1] 2
stri_length(NA)
## [1] NA
...
Remove empty elements from an array in Javascript
...e(/(\r\n|\n|\r)/gm,"")});
Example:
arr = ["hello",0,"",null,undefined,1,100," "]
arr.filter(function(e){return e});
Return:
["hello", 1, 100, " "]
UPDATE (based on Alnitak's comment)
In some situations you may want to keep "0" in the array and remove anything else (null, undefined and "")...
How do I parse a string with a decimal point to a double?
...
this code doesn't work for a number like 100.35 if the system culture uses a comma as the separator. you'd expect it to return a number of about 100, but it returns 10035.
– Lennart
Aug 6 at 11:31
...
AWS Error Message: A conflicting conditional operation is currently in progress against this resourc
...ets or replace buckets, it is not healthy.
Note that you have a limit of 100 buckets for an account (see here). EDIT: Now this limit is a "soft limit" and you can increase it if needed.
Also note that a creation of a bucket takes time and:
...it is not appropriate to make bucket create or de...
trying to animate a constraint in swift
...
SWIFT 4.x :
self.mConstraint.constant = 100.0
UIView.animate(withDuration: 0.3) {
self.view.layoutIfNeeded()
}
Example with completion:
self.mConstraint.constant = 100
UIView.animate(withDuration: 0.3, animations: {
self.view.layoutIfNeeded()
...
Why start an ArrayList with an initial capacity?
... of wasted space changed over time, being 0% some of the time and close to 100% some of the time. Changing the factor from 2 to 1.5 or 4 or 100 or whatever changes the average amount of wasted space and the average amount of time spent copying, but the time complexity remains linear on average no ma...
How do I replace a character at a particular index in JavaScript?
...
100
There is no replaceAt function in JavaScript. You can use the following code to replace any ch...
How to pick an image from gallery (SD Card) for my app?
...
private static final int SELECT_PHOTO = 100;
Start intent
Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, SELECT_PHOTO);
Process result
@Override
protected void onA...