In this exercise, we will take a look at logical operators.
Logical operators allow us to combine multiple True/False expressions and statements into complex conditionals. Using the operators -and, -or, -xor, -not, !, we can test multiple conditions with the equality comparison operators we discussed in the previous exercise.
Truth Table
A simple way to show the output of logical operators is through a truth table.
| x | y | x -and y | x -or y | x -xor y | -not x |
|---|---|---|---|---|---|
| T | T | T | T | F | F |
| T | F | F | T | T | F |
| F | T | F | T | T | T |
| F | F | F | F | F | T |
As shown in the first two columns, imagine x and y are variables that hold the boolean values. The rest of the columns show the output of the corresponding logical operator given the values for x and y for that row. Let’s explore a few PowerShell examples.
-and
The and logical operator is a binary operator that returns True if both statements are True.
-or
The binary or logical operator returns True if either statement returns True.
-xor
This binary operator returns True when only ONE statement is True.
-not and !
Both the -not and ! operators negate the statement that follows. They are unary operators.
Instructions
In the logical_operators.ps1 script file, check if both variables $number_1 and $number_2 are less than 50. Assign the boolean result to a variable called $both_are_less_than_50.
When you’re done, click the Run button.
Check whether the variable $number_1 OR $number_2 is greater than 100. Make the variable $one_is_higher_than_100 equal to its result.
When you’re done, click the Run button.
Check whether ONLY one variable $number_1 or $number_2 is less than or equal to 10 and assign the result to a variable $only_one_is_less_than_10.
When you’re done, click the Run button.
Using one of the two logical operators for negation, -not or !, verify that the variable $name is not equal to the string ‘codecademy’. Make the boolean variable $name_is_not_codecademy equal to its result.
When you’re done, click the Run button.
Run the script from the terminal by typing ./logical_operators.ps1. To check your work, click the Run button.
When prompted, enter your name and any two integers. Press Enter to confirm.