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Why are ToLookup and GroupBy different?
... I ever bother with GroupBy? Why should it exist?
What happens when you call ToLookup on an object representing a remote database table with a billion rows in it?
The billion rows are sent over the wire, and you build the lookup table locally.
What happens when you call GroupBy on such an object...
Object.getOwnPropertyNames vs Object.keys
...
There is a little difference. Object.getOwnPropertyNames(a) returns all own properties of the object a. Object.keys(a) returns all enumerable own properties. It means that if you define your object properties without making some of them enumerable: false these two methods will give you the sa...
Creating range in JavaScript - strange syntax
...guments
How the Number function handles arguments
What Function.prototype.call does
They're rather advanced topics in javascript, so this will be more-than-rather long. We'll start from the top. Buckle up!
1. Why not just Array(5).map?
What's an array, really? A regular object, containing intege...
'size_t' vs 'container::size_type'
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The standard containers define size_type as a typedef to Allocator::size_type (Allocator is a template parameter), which for std::allocator<T>::size_type is typically defined to be size_t (or a compatible type). So for the standard case, they are the same.
However, if you us...
Adding console.log to every function automatically
...there a way to make any function output a console.log statement when it's called by registering a global hook somewhere (that is, without modifying the actual function itself) or via some other means?
...
How do I find which transaction is causing a “Waiting for table metadata lock” state?
...S
We can use INFORMATION_SCHEMA Tables.
Useful Queries
To check about all the locks transactions are waiting for:
USE INFORMATION_SCHEMA;
SELECT * FROM INNODB_LOCK_WAITS;
A list of blocking transactions:
SELECT *
FROM INNODB_LOCKS
WHERE LOCK_TRX_ID IN (SELECT BLOCKING_TRX_ID FROM INNODB_L...
Inject service in app.config
...e into app.config, so that data can be retrieved before the controller is called. I tried it like this:
10 Answers
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How to exclude specific folders or files from validation in Eclipse?
...lder
Click Resource, ResourceFilters
Click "Add"
Set the following Exclude All, Files and Folders, All Children, add an asterisk (*) to the File and Folder Attributes input field (highlighted in the image below)
Note: In Eclipse Indigo you have to Right click the folder and select properties and t...
How to run a background task in a servlet based web application?
... your job here which should run every 5 seconds.
}
}
Yes, that's really all. The container will automatically pickup and manage it.
EJB unavailable? Use ScheduledExecutorService
If your environment doesn't support EJB (i.e. you're not using not a real Java EE server, but a barebones servle...
What is the difference between “#!/usr/bin/env bash” and “#!/usr/bin/bash”?
...en Ubuntu 16.04 if not later).
Another downside is that since you aren't calling an explicit executable, it's got the potential for mistakes, and on multiuser systems security problems (if someone managed to get their executable called bash in your path, for example).
#!/usr/bin/env bash #lends yo...