ColorConsole [Version 1.7.1000] PowerShell 2.0-Export
Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation.
C:\Windows-7>Powershell get-help about_logical_operators -full
# TOPIC
about_Logical_Operators
# SHORT DESCRIPTION
Describes the operators that connect statements in Windows PowerShell.
# LONG DESCRIPTION
The Windows PowerShell logical operators connect expressions and
statements, allowing you to use a single expression to test for multiple
conditions.
For example, the following statement uses the and operator and
the or operator to connect three conditional statements. The statement is
true only when the value of $a is greater than the value of $b, and
either $a or $b is less than 20.
($a -gt $b
) -and
(($a -lt 20
) -or
($b -lt 20
))
Windows PowerShell supports the following logical operators.
Operator Description Example
-------- ------------------------------ ------------------------
-and Logical and. TRUE only when
(1 -eq 1
) -and
(1 -eq 2
)
both statements are TRUE. False
-or Logical or. TRUE when either
(1 -eq 1
) -or
(1 -eq 2
)
or both statements are TRUE. True
-xor Logical exclusive or. TRUE
(1 -eq 1
) -xor
(2 -eq 2
)
only when one of the statements False
is TRUE and the other is FALSE.
-not Logical not. Negates the -not
(1 -eq 1
)
statement that follows it. False
! Logical not. Negates the !
(1 -eq 1
)
statement that follows it. False
(Same as -not
)
Note: The previous examples also use the equal to comparison
operator
(-eq
). For more information, see about_Comparison_Operators.
The examples also use the Boolean values of integers. The integer 0
has a value of FALSE. All other integers have a value of TRUE.
The syntax of the logical operators is as follows:
<statement>
{-AND | -OR | -XOR
} <statement>
{! | -NOT
} <statement>
Statements that use the logical operators return Boolean
(TRUE or FALSE
)
values.
The Windows PowerShell logical operators evaluate only the statements
required to determine the truth value of the statement. If the left operand
in a statement that contains the and operator is FALSE, the right operand
is not evaluated. If the left operand in a statement that contains
the or statement is TRUE, the right operand is not evaluated. As a result,
you can use these statements in the same way that you would use
the If statement.
SEE ALSO
about_Operators
Compare-Object
about_Comparison_operators
about_If
C:\Windows>powershell
get-help about_methods -full
