operator
switch expression | switch expression
    
 The operator | is a logical operator that evaluates to true if either or both of the operands
        evaluates to true. If both evaluate to false, then the result of | is also false. If the left-hand operand evaluates to true, the second is not evaluated. 
      
 For example:
        
do when a < b | c < d output "Hello, World!%n" done
 The keyword or is a deprecated form of |.