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Programming-Idioms

  • Scala
  • C#
  • Python
  • Elixir

Idiom #4 Create a function

Create a function which returns the square of an integer

@spec square(integer) :: integer
def square(x) when is_integer(x), do: x*x

The guard guarantees that the return value is an integer. The spec lets dialyzer warn you if you use this without something guaranteed to be an integer, or where the return value is used somewhere that an integer is invalid.
def square(x:Int): Int = x*x
void Square(ref int x)
{
    x = x * x;
}

The ref keyword indicates that a value is passed by reference.
To use this function you gonna need to type ref before your value
int Square(int x)
{
    return x * x;
}
int Square(int x) => (int)Math.Pow(x, 2);
double Square(int value) => System.Math.Pow(value, 2);

Math.Pow returns a double.
By default, this method will be private.
def square(x):
    return x**2

You can use power operator
square = lambda x: x * x
def square(x):
    return x*x

You don't have to explicitly write the return type
function Square (X : Integer) return Integer is
begin
   return X * X;
end Square;
New implementation...
< > ⌨
programming-idioms.org 
@spec square(integer) :: integer
def square(x) when is_integer(x), do: x*x
def square(x:Int): Int = x*x
void Square(ref int x)
{
    x = x * x;
}
int Square(int x)
{
    return x * x;
}
int Square(int x) => (int)Math.Pow(x, 2);
double Square(int value) => System.Math.Pow(value, 2);
def square(x):
    return x**2
square = lambda x: x * x
def square(x):
    return x*x
function Square (X : Integer) return Integer is
begin
   return X * X;
end Square;
int square(int x){
  return x*x;
}
let square x = x*x
(defn square [x]
  (* x x))
int square(int x){
  return x*x;
}
alias fun = (in a){return a * a;};
int square(int x) {
   return x*x;
}
int square(int x) => x * x;
-spec square(integer()) -> integer().
square(X) when is_integer(X) -> X * X.
module foo
  implicit none
contains
  function square(i) result(res)
    integer, intent(in) :: i
    integer :: res
    res = i * i
  end function square
end module foo

func square(x int) int {
  return x*x
}
int square(int x){
  return x*x
}
square x = x * x
square x = x**2
square x = x^2

const square = (x) => x * x;
function square(x) { 
	return x * x;
}
const square = n => n**2
const square = (number) => Math.pow(number, 2);
int square(int a) { return (int) pow(a, 2); }
int square(int x){
  return x*x;
}
int square(int a) { return a * a; }
BigInteger square(BigInteger a) {
    return a.multiply(a);
}
Function<Integer,Integer> squareFunction = x -> x * x;
interface F { int get(int a); }
F square = x -> x * x;
fun square(x: Int) = x * x
(defun square (x)
  (* x x))
function square(x)
	return x*x
end
int square(int x) {
  return x*x;
}
function square(int $x): int
{
    return $x * $x;
}

// square(4) -> 16
// square(3.4) -> Uncaught TypeError: Argument 1 passed to square() must be of the type int, float given
Function square(x: Integer): Integer;
Begin
  Result := x*x;
End;
sub square {
    my ($i) = @_;
    return $i ** 2;
}
def square(x) = x*x
def square(x)
  x*x
end
fn square(x : u32) -> u32 { x * x }
(define square
    (lambda (x)
        (* x x)))
(define (square x)
    (* x x))
[:anInteger | anInteger squared]
Function Square(x As Integer) As Integer
    Return x * x
End Function
Function Square(x As Integer) As Double
    Return x ^ 2
End Function