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- Added main concept: bools - Added concept exercise: pac-man - Added minor concept: comment-based help
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| { | ||
| "blurb": "Boolean type in PowerShell, true and false values and logical operators.", | ||
| "authors": ["glaxxie"], | ||
| "contributors": [] | ||
| } |
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| # About | ||
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| ## Booleans | ||
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| PowerShell has the [`bool`][booleans] type to represents true and false values. | ||
| In this type there are only two values: `True` and `False`. | ||
| You can bind these values to variables with the prefix `$`: | ||
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| ```powershell | ||
| > $TrueVar = $true | ||
| > $FalseVar = $FALSE | ||
| #Case senstitivity doesn't matter here | ||
| ``` | ||
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| We can use [logical operators][logical-operators] like `-and`, `-or`, and `-not` to combine and evaluate Boolean expressions. | ||
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| ```powershell | ||
| > $TrueVar = $true -and $true | ||
| > $FalseVar = $true -and $false | ||
| > $TrueVar = $true -or $false | ||
| > $FalseVar = $false -or $false | ||
| > $TrueVar = -not $false | ||
| > $FalseVar = -not $true | ||
| ``` | ||
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| ## Conversion and truthiness | ||
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| PowerShell can implicitly treat any type as a Boolean. | ||
| However you can also use the Boolean type accelerator `[bool]` for explicit conversion. | ||
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| Here are some general rules that PowerShell use to convert other types to Boolean values: | ||
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| $false: | ||
| - Emptry strings like `''` or `""` | ||
| - Null values like `$null` | ||
| - Numeric type with the value of zero (0) | ||
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| $true: | ||
| - Non-empty strings | ||
| - Instances of any other non-collection type | ||
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| ```powershell | ||
| > [bool] 0 | ||
| False | ||
| > [bool] 0.0 | ||
| False | ||
| > [bool] "" | ||
| False | ||
| > [bool] "Hello" | ||
| True | ||
| > [bool] 1234 | ||
| True | ||
| ``` | ||
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| For in depth rules about converting Boolean values from collection types, please read [here][collection-conversion]. | ||
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| [booleans]: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_booleans?view=powershell | ||
| [logical-operators]: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_logical_operators | ||
| [collection-conversion]: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_booleans?#converting-from-collection-types |
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| # Introduction | ||
|
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||
|
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| PowerShell has the [`bool`][booleans] type to represents true and false values. | ||
| In this type there are only two values: `True` and `False`. | ||
| You can bind these values to variables with the prefix `$`: | ||
|
|
||
| ```powershell | ||
| > $TrueVar = $true | ||
| > $FalseVar = $FALSE | ||
| #Case senstitivity doesn't matter here | ||
| ``` | ||
|
|
||
| We can use [logical operators][logical-operators] like `-and`, `-or`, and `-not` to combine and evaluate Boolean expressions. | ||
|
|
||
| ```powershell | ||
| > $TrueVar = $true -and $true | ||
| > $FalseVar = $true -and $false | ||
| > $TrueVar = $true -or $false | ||
| > $FalseVar = $false -or $false | ||
| > $TrueVar = -not $false | ||
| > $FalseVar = -not $true | ||
| ``` |
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| [ | ||
| { | ||
| "url": "https://en.wikipedia.org/wiki/Truth_table", | ||
| "description": "truth table" | ||
| }, | ||
| { | ||
| "url": "https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_operator_precedence", | ||
| "description": "operator precedence" | ||
| } | ||
| ] |
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