Ruby array.select 多行块

Question

I am filtering an array in ruby and using a .select block to do so. The conditions are sufficiently complex that a single line block is hideous but not that large so a separate method seems like overkill. Thus I want to use a multiline block. However I am unsure of the syntax.

filtered_array = base_array.select do |elem|
    return false if condition1
    return false if condition2
    return true
end

The above is clearly incorrect as return exits the method, not the block but gives an idea of what I am looking for.

I could also use multiple select statements but that seems to obfuscate what I am trying to do. Note that the above conditions are sufficiently complex that using logical operators to bind them results in a mess.

Answer 1

你想要的是next而不是return 。

Answer 2

Edit: Just saw this: "using logical operators to bind them results in a mess." Could you provide the actual conditions?

filtered_array = base_array.select do |elem|
    condition1 && condition2
end

Answer 3

You should probably just use:

next(true)

However if that doesn't jive with you then do this:

my_array.select do |x|
  # bool = false ### optional, uncomment this if you prefer
  if x.id == 1
    bool = true
  end
  bool
end

Answer 4

Seems like this could be handled with a case statement:

filtered_array = base_array.select do |elem|
  case
  when condition1
    false
  when condition2
    false
  else
    true
  end
end

Answer 5

You can use next with unless combination till penultimate conditions

filtered_array = base_array.select do |elem|
  next unless condition1
  condition2
end