如何將字典數組整理成數組字典？

Question

我有這樣的數據：

list = [ 
     {name:'apple', category: "fruit", price: 1.22 }, 
     {name:'pear', category: "fruit", price: 2.22 }, 
     {name:'coke', category: "drink", price: 3.33 }, 
    {name:'sprite', category: "drink", price: .44 }, 
    ]; 

而且我想創建鍵安裝在A類字典，它的值是一個包含該類別的所有產品的數組。我試圖這樣做失敗：

var tmp = {}; 
    list.forEach(function(product) { 
     var idx = product.category ; 
     push tmp[idx], product; 
    }); 
    tmp; 

Answer 1

function dictionary(list) { 
    var map = {}; 
    for (var i = 0; i < list.length; ++i) { 
     var category = list[i].category; 
     if (!map[category]) 
      map[category] = []; 
     map[category].push(list[i].name); // add product names only 
     // map[category].push(list[i]); // add complete products 
    } 
    return map; 
} 
var d = dictionary(list); // call 

您可以測試它jsfiddle。