Sometimes one would like to pass names of columns from a data frame to a function. They may be provided as strings and used in a function using [[. Let's take a look at the following example, which prints to R console basic stats of selected variables:
basic.stats <- function(dset, vars){
f...
Scala supports lazy evaluation for function arguments using notation: def func(arg: => String). Such function argument might take regular String object or a higher order function with String return type. In second case, function argument would be evaluated on value access.
Please see the example...
In a basic implementation the task module must define a run/1 function that takes a list of arguments. E.g. def run(args) do ... end
defmodule Mix.Tasks.Example_Task do
use Mix.Task
@shortdoc "Example_Task prints hello + its arguments"
def run(args) do
IO.puts "Hello ...
Always use Named Arguments to optional parameters, to avoid potential bugs when the method is modified.
class Employee
{
public string Name { get; private set; }
public string Title { get; set; }
public Employee(string name = "<No Name>", string title = "<...
One of the major use case when a developer needs to take mutability into account is when passing arguments to a function. This is very important, because this will determine the ability for the function to modify objects that doesn't belong to its scope, or in other words if the function has side ef...
int sum (int x, ...) {
int result = x;
va_list list = va_list ();
for (int? y = list.arg<int?> (); y != null; y = list.arg<int?> ()) {
result += y;
}
return result;
}
int a = sum (1, 2, 3, 36);
With this function, you can pass as many int as you w...
enum ReadResult{
case Successful
case Failed
case Pending
}
struct OutpuData {
var data = Data()
var result: ReadResult
var error: Error?
}
func readData(from url: String, completion: @escaping (OutpuData) -> Void) {
var _data = OutpuData(data: Data(), ...
The extra arguments add results to predicates of a DCG clause, by decorating the derivation tree. For example, it's possible to create a algebraic grammar that computes the value at the end.
Given a grammar that supports the operation addition:
% Extra arguments are passed between parenthesis afte...
A common mistake is to forget surrounding compound function arguments with parentheses, leading to type errors.
# string_of_int 1+1;;
Error: This expression has type string but an expression was expected of type int
This is because of the precedence. In fact, the above evaluates to
# (string...
You can also pass arguments with a message to work with.
We will use the classed from our previous example and extend them. In the receiving part, right behind the Subscribe method call add the type of the argument you are expecting. Also make sure you also declare the arguments in the handler sign...
ArgumentCaptor will to receive the actual invocation arguments that has been passed to method.
ArgumentCaptor<Foo> captor = ArgumentCaptor.forClass(Foo.class);
verify(mockObj).doSomethind(captor.capture());
Foo invocationArg = captor.getValue();
//do any assertions on invocationArg
For ...
if len(sys.argv) != 4: # The script name needs to be accounted for as well.
raise RuntimeError("expected 3 command line arguments")
f = open(sys.argv[1], 'rb') # Use first command line argument.
start_line = int(sys.argv[2]) # All arguments come as strings, so need to ...
The splat operator removes individual elements of an array and makes them into a list. This is most commonly used to create a method that accepts a variable number of arguments:
# First parameter is the subject and the following parameters are their spouses
def print_spouses(person, *spouses)
s...
Suppose you want the user to select keywords from a menu, we can create a script similar to
#!/usr/bin/env bash
select os in "linux" "windows" "mac"
do
echo "${os}"
break
done
Explanation:
Here select keyword is used to loop through a list ...
