用表达式 switch 语句

条件也可以是表达式:

$myInput = 0

switch($myInput) {
    # because the result of the expression, 4, 
    # does not equal our input this block should not be run.
    (2+2)  { 'True. 2 +2 = 4' }

    # because the result of the expression, 0, 
    # does equal our input this block should be run.
    (2-2) { 'True. 2-2 = 0' }

    # because our input is greater than -1 and is less than 1 
    # the expression evaluates to true and the block should be run.
    { $_ -gt -1 -and $_ -lt 1 } { 'True. Value is 0' }
}

#Output
True. 2-2 = 0
True. Value is 0