遍歷Rails中的項目數組的語法問題

Question

我正在嘗試將一些數據從jQuery發布到Web服務：

  var jtvals={};
  jtvals['line_items']=[];
  var g={"name":"jon"};
  var h={"name":"joan"};

  jtvals['line_items'].push(g);
  jtvals['line_items'].push(h);

  $.ajax({
    url: '/arc/v1/api/calculate_line_items',
    type: 'POST',
    data: jtvals,
    dataType: 'json'
  }).done(function(r){
    alert('this is finished');
  });

扶手：

  def calculate_line_items
    line_items=params[:line_items]
    puts line_items
    puts line_items.count
    puts "DO LOOP:"

    line_items.each_with_index do |tmp_line_item, idx|
        puts "idx:"
        puts idx

        puts "about to give you:"
        puts tmp_line_item
        puts "after giving you:"

和參數看起來像這樣：

但是，它出現以下錯誤：

  Parameters: {"line_items"=>{"0"=>{"name"=>"jon"}, "1"=>{"name"=>"joan"}}}
{"0"=>{"name"=>"jon"}, "1"=>{"name"=>"joan"}}
2
DO LOOP:
idx:
0
about to give you:
0
{"name"=>"jon"}
after giving you:
Completed 500 Internal Server Error in 2ms (ActiveRecord: 0.0ms)

TypeError (no implicit conversion of String into Integer):
  app/controllers/api_orders_controller.rb:41:in `[]'
  app/controllers/api_orders_controller.rb:41:in `block in calculate_line_items'
  app/controllers/api_orders_controller.rb:33:in `each_with_index'
  app/controllers/api_orders_controller.rb:33:in `calculate_line_items'

而且我不確定為什么將數組的鍵作為輸出。 我該如何解決？

Answer 1

如果您希望tmp_line_item返回{"name"=>"jon"}和{"name"=>"joan"} ，請嘗試：

line_items.each_with_index do |(k, tmp_line_item), idx|
  ...