There is no right or wrong for multiple and one, only right or wrong in the corresponding scene.
many lines
One is that there can be multiple items, such as fuzzy search for letters, and then display the list.
findUserList
There are many such items, return success.
A
One is that there can only be one, for example, click a user in the list.
findUser
There are multiple items of this kind, and false is returned.
Prompt: "There should be one, but there are actually more."