js: the difference between return [expression], return false, return true, return

1、return [ expression ] 

2, return false, prevent the default behavior,

　　① When binding a click event to the a tag, because the a tag has a default click event, and you don't want it to perform the default behavior, you can use return false to prevent it

　　 ②The default submission behavior of the form form

3. return true will continue the operation

4. Separate return, the following code will not continue to execute, return in advance