A switch statement uses the following generalized notation:

switch [-regex|-wildcard][-casesensitive] (<value>) { 
    <condition> { <statements> } 
    <condition> { <statements> } 
} 

The casesensitive parameter applies when testing conditions against a string value.

The switch command can also be used to work on the content of a file using the following notation:

switch [-regex|-wildcard][-casesensitive] -File <Name> { 
    <condition> { <statements> } 
    <condition> { <statements> } 
} 

The File parameter can be used to select from a text file (line by line). The switch statement differs from conditions written using if-elseif in one important respect. The switch statement will not stop testing conditions unless the break keyword is used, for example:

$value = 1 
switch ($value) { 
    1 { Write-Host 'value is 1' } 
    1 { Write-Host 'value is still 1' } 
} 

Using break, as shown here, will exit the switch statement after a match:

$value = 1 
switch ($value) { 
    1 { Write-Host 'value is 1'; break } 
    1 { Write-Host 'value is still 1' } 
} 

The default keyword provides the same functionality as the else statement when using if, for example:

$value = 2 
switch ($value) { 
    1       { Write-Host 'value is 1' } 
    default { Write-Host 'No conditions matched' } 
} 

A switch statement can test more than one value at once; however, break applies to the entire statement, not just a single value. For example, without break, both of the following Write-Host statements execute:

switch (1, 2) {
    1 { Write-Host 'Equals 1' } 
    2 { Write-Host 'Equals 2' } 
} 

If the break keyword is included, as shown here, only the first executes:

switch (1, 2) { 
    1 { Write-Host 'Equals 1'; break } 
    2 { Write-Host 'Equals 2' } 
}