Ruby unless usage

The ruby unless expression runs only when the condition is false.CodeBut it does not understand the logic combination with the condition "& |". Whether it is false or false to run the unless code block, or false | false to continue running.

In fact, this problem is very simple, but I never thought about it. unless only indicates whether the condition is false or true. If the & or | caozuofu.html "target =" _ blank "> operator is used, it does not matter.
& Logical operators, or the following conditions are run only when the preceding conditions are true

Puts 'OK' unless 1 & nil # If the entire condition expression returns nil, The unless condition is true and okputs 'OK' unless 1 is printed. | nil # If the entire condition expression returns 1, not true, no output puts 'OK' unless nil | false # The entire conditional expression returns false, true, print OK