How to use the «If» command ?

if (1 -eq 2) {echo "True"} else {echo "False"}

You can use any of the comparison operators in your «If» command :

-eq	Equal
-ne	Not equal
-gt	Greater than
-ge	Greater than or equal to
-lt	Less than
-le	Less than or equal to
-like	Wild card comparison : “powershell” –like “pow*”
-notlike	Negative wild card comparison
-match	Regular expression comparison
-notmatch	Negative Regular expression comparison
-contains	“powershell” –contains “Shell”
-notcontains	“powershell” –notcontains “Shell”

All those comparison operators are case-insensitive.

You ca also use any of the logical operators :

-and
-or
-xor
-not
!