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In this exercise, we will discuss the assignment and unary operators.

#### Assignment Operators

We can use assignment operators to assign, change, or append values to variables. The general syntax of the assignment operators is as follows: `<Variable> <Assignment-Operator> <Value>`.

We are already familiar with one of the assignment operators, `=`. It is used to assign a value to a variable. Other assignment operators include `+=`, `-=`, `*=`, `/=`, and `%=`. These operators are called compound assignment operators.

Notice that an arithmetic operator precedes the `=`. This means compound assignment operators perform operations on the values before the assignment. Consider the following example:

``````PS > \$number = 75
PS > \$number_1 = \$number / 3
PS > \$number_1
25
PS > \$number_2 = \$number
PS > \$number_2 /= 3
PS > \$number_2
25``````

We can use the `/=` compound assignment operator as a shorthand for dividing a variable and saving the result to the same variable. As shown above, the statements `\$number_1 = \$number / 3` and `\$number_2 /= 3` behave similarly.

#### Assignment Operators on Environment Variables

Recall that environment variables are of type `String` and that the `+` arithmetic operator can concatenate strings. We can append the `+=` compound assignment operator to an existing environment variable.

``````PS > \$Env:EXAMPLE_ENV_VAR = "custom value"
PS > \$Env:EXAMPLE_ENV_VAR += "; another value"
PS > \$Env:EXAMPLE_ENV_VAR
custom value; another value``````

Note: Environment variables that have multiple values are separated by a semicolon `;` on Windows. For example, the `PATH` environment variable specifies the directories in which executable programs are located. Utilizing `;` with the `+=` assignment operator, we can add new directories to `PATH`.

#### Unary Operators

Unary operators operate on a single variable operand. `++` and `--` are the increment and decrement operators and increase or decrease the value of a variable by 1, respectively.

``````PS > \$i = 0
PS > \$i++
PS > \$i
1

PS > \$i--
PS > \$i
0``````

Unary operators are an easily readable way to increase or decrease a variable value by `1`.

### Instructions

1.

In the script file, `number_one.ps1`, use the multiplication compound assignment operator to multiply the variable `\$number` by `3`.

When you’re done, click the Run button.

2.

On the next line, use the addition compound assignment operator to add `6` to the variable `\$number` and click Run.

3.

On the next line, use the division compound assignment operator to divide the variable `number` by `3` and click Run.

4.

On the next line, use the subtraction compound assignment operator to subtract the variable `\$original_number` from the variable `\$number`.

When you’re done, click the Run button.

5.

On the next line, use a unary operator to subtract `1` from the variable `\$number` and click Run.

6.

Finally, type `./number_one.ps1` on the terminal to run the script. Be sure to click the Run button to check your work.

When the script runs, you’ll be prompted to type a number. Enter a number into the terminal and press Enter

Was `1` your final number? Feel free to re-run the script to input a different integer. The final number will always be `1`!