如何从对象中提取值？

--- 
- !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）如何从对象中提取值？

我怎样才能得到post_id作为阵列的价值？ @arr = [ 5,6,3,7,1 ] 现在我想得到这些post_id这些职位。这是正确的吗？ @p = Post.where(:id=>@arr)

来源

2011-07-17 railshero

无需-1虽然 – corroded

问，如果这是正确的，你可以通过简单地尝试它自己回答的问题。你告诉我们，它工作吗？它做你想做的事吗？如果你尝试过它并没有奏效，那么你有更好的问题来打击人们。正如Thilo所说，你需要在任何人回答你的问题之前开始接受答案 –

@corroded不是我:) – Thilo

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

来源

2011-07-17 11:43:29 kain

如何从对象中提取值？

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