01.ps1

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#  VARIABLES
#
#  A variable is a symbol that represents a quantity that may vary.
#
#  identifier = value;

$age = 25       # The value 25 is assigned to variable age



#  BASIC DATA TYPES
$sea_level = 25                           # Integer
$temperature = -3.82                      # Real number (double)
$name = 'Nacho López'                     # String
$has_car = $true                          # Boolean (only two values: true or false)



#  ARITHMETIC OPERATIONS WITH NUMBERS
$x = 5
$y = 2

$z = $x + $y       # Addition.                                     Result: 7.
$z = $x - $y       # Subtraction.                                  Result: 3.
$z = $x * $y       # Multiplication.                               Result: 10.
$z = $x / $y       # Division.                                     Result: 2.5.
$z = $x % $y       # Modulo (remainder of the integer division).   Result: 1.

$z = $z + 1        # Increase the value of z by 1.                 Result: 2.
$z = $z - 1        # Decrease the value of z by 1.                 Result: 1.

$z = 50 - $x * 6 / -0.5        #
$z = (50 - $x) * 6 / -0.5      # The order of operations is as in mathematics
$z = (50 - $x * 6) / -0.5      #

$z = 2 * $z + 3                # Remember: the symbol = assigns a value to the variable



#  BASIC OPERATIONS WITH STRINGS
$a = 'GNU/'
$b = 'Linux'
$c = $a + $b                                   # Concatenation     Result: 'GNU/Linux'.
$c = $a * 3                                    # Repetition        Result: 'GNU/GNU/GNU/'.



#  PRINT VARIABLES ON SCREEN

Write-Output('Hello, world!')            # Prints on screen: Hello, world!
Write-Output($x)                         # Prints the variable x

#  You can print on screen strings and variables
Write-Output('I have bought ' + $x + ' oranges and ' + $y + ' lemons.')



#  DATA TYPE CONVERSION

$position = '5'
$calories = '95.4'
$altitude = -544.432

$position_int = [int] $position            # Convert to integer.
$calories_dbl = [double] $calories         # Convert to double.
$altitude_str = [string] $altitude         # Convert to string.

$position_type = $position_int.GetType().FullName    # Type: integer.
$calories_type = $calories_dbl.GetType().FullName    # Type: double.
$altitude_type = $altitude_str.GetType().FullName    # Type: string.