如何從對象中提取值？

--- 
- !ruby/object:Comment 
    attributes: 
    post_id: '5' 
    changed_attributes: {} 
    previously_changed: {} 
    attributes_cache: {} 
    marked_for_destruction: false 
    destroyed: false 
    readonly: false 
    new_record: false 
- !ruby/object:Comment 
    attributes: 
    post_id: '6' 
    changed_attributes: {} 
    previously_changed: {} 
    attributes_cache: {} 
    marked_for_destruction: false 
    destroyed: false 
    readonly: false 
    new_record: false 
- !ruby/object:Comment 
    attributes: 
    post_id: '3' 
    changed_attributes: {} 
    previously_changed: {} 
    attributes_cache: {} 
    marked_for_destruction: false 
    destroyed: false 
    readonly: false 
    new_record: false 
- !ruby/object:Comment 
    attributes: 
    post_id: '7' 
    changed_attributes: {} 
    previously_changed: {} 
    attributes_cache: {} 
    marked_for_destruction: false 
    destroyed: false 
    readonly: false 
    new_record: false 
- !ruby/object:Comment 
    attributes: 
    post_id: '1' 
    changed_attributes: {} 
    previously_changed: {} 
    attributes_cache: {} 
    marked_for_destruction: false 
    destroyed: false 
    readonly: false 
    new_record: false

（http://pastebin.com/J1angM6d）如何從對象中提取值？

我怎樣才能得到post_id作爲陣列的價值？ @arr = [ 5,6,3,7,1 ] 現在我想得到這些post_id這些職位。這是正確的嗎？ @p = Post.where(:id=>@arr)

來源

2011-07-17 railshero

無需-1雖然 – corroded

問，如果這是正確的，你可以通過簡單地嘗試它自己回答的問題。你告訴我們，它工作嗎？它做你想做的事嗎？如果你嘗試過它並沒有奏效，那麼你有更好的問題來打擊人們。正如Thilo所說，你需要在任何人回答你的問題之前開始接受答案 –

@corroded不是我:) – Thilo

@p = Post.find(my_collection.map(&:post_id))

來源

2011-07-17 11:43:29 kain

如何從對象中提取值？

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