Just like in mathematics, the order in which operators are evaluated matters in programming. Operator precedence in PowerShell is as follows:
( )++--!-not*/%+--is-isnot-as-eq-ne-gt-ge-lt-le-contains-notContains-and-or-xor=+=-=*=/=%=
Precedence order is the order in which PowerShell evaluates the operators if multiple operators are used in the same expression. Parentheses ( ) take the highest priority, and the assignment operators have the least priority. Operators on the same level are evaluated from left to right. Consider the example below.
The multiplication operator * has higher precedence than the subtraction operator -. Thus, in the example above, the expression 1 * 5 is evaluated first, resulting in 5 - 5, which equals 0.
We can use parentheses to override the precedence order and force PowerShell to evaluate a part of an expression first.
Instructions
In the script file named expression_precedence.ps1, we have three expressions that return 8, 6, and False respectively. These results are not what we are looking for. Let’s use parentheses ( ) to acquire the desired results.
For expression_1, we want 4 as a result. Put parentheses around the expression 2 + 4 * 2.
Click Run when you’re done and your result will output in the terminal.
We want 2 to be the result of expression_2. Enclose the expression 3 * (2 + 1) with parentheses and click Run.
The way it is now, expression_3 is currently returning False. We want this to be True.
Remove parentheses around 3 + 2 -ne 5 and put parentheses around 2 -ne 5 instead.
Remove parentheses around 5 -gt 8 and put parenthesis around the -gt operator expression 2 * 5 -gt 8.
Click the Run button to run the script file expression_precedence.ps1 one last time. The three expressions should now return 4, 2, and True respectively.