The power Shell's variables, arrays, objects, and operators are detailed

"Variables and Constants"

Variable: The amount that will change, temporarily storing the data so that you can call it later

Constants: Quantity that does not change

One, variable and array

"Variable", like in memory to divide a space, you can store some data, can only store a pair of

A line corresponding to an object

"Arrays", like dividing multiple storage spaces in memory, containing subscripts, can hold data from multiple objects

(1), using variable

A variable (Variable) is a memory cell in which a value is stored, and in PowerShell, the variable is represented by a single word literal string that begins with the symbol $

1, the creation and modification of variables

Format:$< variable name >=< variable value >

"The characteristics of the variable"

You do not have to declare variable types in PowerShell, you can be integers, floating-point numbers, characters, strings, arrays, and so on. For example: $sum =1; $sum =1.5; $arry = "abc", "EFG"

Variables can be created and used directly within the console

2, display the value of the variable

Enter the name of the variable in the console (beginning with $)

Use get-variable to view variables (get-variable variable names)

3, the operation of the variable

Calculate the radius of a circle

Output calculation results

"As shown above, the steps to create a variable and perform a mathematical operation"

1 Create variable $pi and assign a value of 3.1416

2) Prompts the user to enter the radius of the circle, enter a value of 12

Read-host receives user input, the stored value type is a character type (String), the numeric calculation must be converted to a numeric type, and "decimal" means that the variable is cast from character to Decimal, and decimal is a cast numeric type, representing "decimal"

3 Calculate the area of the circle with the radius of the input

The calculation formula of the circle is: area=pi* (r*r), in PowerShell, the square can be multiplied by two numbers, $r receive the user input value, the variable $area is the area of the circle, * is the multiplication operator of the PowerShell, $area = $pi * ($R * $R). () represents precedence in multiplication operations

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