DT[where, select|update|do, by] syntax is used to work with columns of a data.table.
The "where" part is the i argument
The "select|update|do" part is the j argument
These two arguments are usually passed by position instead of by name.
Our example data below is
mtcars =...
<PROJECT_ROOT>\app\build.gradle is specific for app module.
<PROJECT_ROOT>\build.gradle is a "Top-level build file" where you can add configuration options common to all sub-projects/modules.
If you use another module in your project, as a local library you would have another...
First install the .NET Core SDK by going through the installation instructions for the platform of your choice:
Windows
OSX
Linux
Docker
After the installation has completed, open a command prompt, or terminal window.
Create a new directory with mkdir hello_world and change into the ne...
R is able to access the current date, time and time zone:
Sys.Date() # Returns date as a Date object
## [1] "2016-07-21"
Sys.time() # Returns date & time at current locale as a POSIXct object
## [1] "2016-07-21 10:04:39 CDT"
as.numeric(Sys...
To start coding in the first place, you have to right click your VBA Project in the left list and add a new Module.
Your first Hello-World Code could look like this:
Sub HelloWorld()
MsgBox "Hello, World!"
End Sub
To test it, hit the Play-Button in your Toolbar or simply hit the...
If you wish to copy the contents of a slice into an initially empty slice, following steps can be taken to accomplish it-
Create the source slice:
var sourceSlice []interface{} = []interface{}{"Hello",5.10,"World",true}
Create the destination slice, with:
Length =...
The family of x86 assembly languages represents decades of advances on the original Intel 8086 architecture. In addition to there being several different dialects based on the assembler used, additional processor instructions, registers and other features have been added over the years while still r...
Approximate-number data types for use with floating point numeric data.
SELECT CAST( PI() AS FLOAT) --returns 3.14159265358979
SELECT CAST( PI() AS REAL) --returns 3.141593
Data types that represent monetary or currency values.
Data typeRangeStoragemoney-922,337,203,685,477.5808 to 922,337,203,685,477.58078 bytessmallmoney-214,748.3648 to 214,748.36474 bytes
Binary data types of either fixed length or variable length.
Syntax:
BINARY [ ( n_bytes ) ]
VARBINARY [ ( n_bytes | max ) ]
n_bytes can be any number from 1 to 8000 bytes. max indicates that the maximum storage space is 2^31-1.
Examples:
SELECT CAST(12345 AS BINARY(10)) -- 0x0000000000000000...
String data types of either fixed length or variable length.
Syntax:
CHAR [ ( n_chars ) ]
VARCHAR [ ( n_chars ) ]
Examples:
SELECT CAST('ABC' AS CHAR(10)) -- 'ABC ' (padded with spaces on the right)
SELECT CAST('ABC' AS VARCHAR(10)) -- 'ABC' (no padding due to variable character)
SELE...
UNICODE string data types of either fixed length or variable length.
Syntax:
NCHAR [ ( n_chars ) ]
NVARCHAR [ ( n_chars | MAX ) ]
Use MAX for very long strings that may exceed 8000 characters.
Long vectors with long runs of the same value can be significantly compressed by storing them in their run-length encoding (the value of each run and the number of times that value is repeated). As an example, consider a vector of length 10 million with a huge number of 1's and only a small number o...
In Python 3, many of the dictionary methods are quite different in behaviour from Python 2, and many were removed as well: has_key, iter* and view* are gone. Instead of d.has_key(key), which had been long deprecated, one must now use key in d.
In Python 2, dictionary methods keys, values and items ...
fn main() {
let maybe_cake = Some("Chocolate cake");
let not_cake = None;
// The unwrap method retrieves the value from the Option
// and panics if the value is None
println!("{}", maybe_cake.unwrap());
// The expect method works much like the un...
Fixnum#to_s takes an optional base argument and represents the given number in that base:
2.to_s(2) # => "10"
3.to_s(2) # => "11"
3.to_s(3) # => "10"
10.to_s(16) # => "a"
If no argument is provided, then it represents the number in bas...
The Arbitrary class is for types that can be randomly generated by QuickCheck.
The minimal implementation of Arbitrary is the arbitrary method, which runs in the Gen monad to produce a random value.
Here is an instance of Arbitrary for the following datatype of non-empty lists.
import Test.QuickC...
It's possible to attach an object to an existing object as if there was a new property. This is called association and allows one to extend existing objects. It can be used to provide storage when adding a property via a class extension or otherwise add additional information to an existing object.
...
