Javascript配列からネストしたオブジェクトを作成する

Question

私はオブジェクトの配列を持っています。各アイテムにはパレットIDが記載されています。ネストされたオブジェクトを作成して、ネストされたオブジェクトがサブカテゴリと同程度になるようにしたい。以下の入力と期待される出力。どのように私はプレーンJSでこれを達成することができますか？

var inputArr = [ 
 
    { 
 
    category_id: 1, 
 
    parent_category_id: 3, 
 
    title: "category1" 
 
    }, 
 
    { 
 
    category_id: 2, 
 
    parent_category_id: 1, 
 
    title: "category2" 
 
    }, 
 
    { 
 
    category_id: 3, 
 
    title: "category3" 
 
    }, 
 
    { 
 
    category_id: 4, 
 
    parent_category_id: 1, 
 
    title: "category4" 
 
    }, 
 
    { 
 
    category_id: 5, 
 
    parent_category_id: 2, 
 
    title: "category5" 
 
    } 
 
] 
 

 

 
var expectedOutput = { 
 
    category_id: 3, 
 
    title: "category3", 
 
    subcategories: [ 
 
    { 
 
     category_id: 1, 
 
     subcategories: [ 
 
     { 
 
     category_id: 2, 
 
     title: "category2", 
 
     subcategories: [ 
 
      { 
 
      category_id: 5, 
 
      title: "category5" 
 
      } 
 
     ] 
 
     }, 
 
     { 
 
     category_id: 4, 
 
     title: "category4" 
 
     } 
 
     ] 
 
    } 
 
    ] 
 
}

Answer 1

var inputArr = [ 
 
    { 
 
     category_id: 1, 
 
     parent_category_id: 3, 
 
     title: "category1" 
 
    }, 
 
    { 
 
     category_id: 2, 
 
     parent_category_id: 1, 
 
     title: "category2" 
 
    }, 
 
    { 
 
     category_id: 3, 
 
     title: "category3" 
 
    }, 
 
    { 
 
     category_id: 4, 
 
     parent_category_id: 1, 
 
     title: "category4" 
 
    }, 
 
    { 
 
     category_id: 5, 
 
     parent_category_id: 2, 
 
     title: "category5" 
 
    } 
 
]; 
 

 
var temp = []; 
 
var parent; 
 

 
for (var i = 0; i < inputArr.length; i++) { 
 
    
 
    if (temp[inputArr[i].category_id]) { 
 
    Object.assign(temp[inputArr[i].category_id], inputArr[i]); 
 
    } else { 
 
    temp[inputArr[i].category_id] = inputArr[i]; 
 
    // uncomment the following assignment to add empty subcategories 
 
    // array to leaf nodes for consistency. 
 
    // temp[inputArr[i].category_id].subcategories = []; 
 
    } 
 

 
    var parentId = inputArr[i].parent_category_id; 
 
    if (!parentId) { 
 
    parent = temp[inputArr[i].category_id]; 
 
    } else { 
 
    if (!temp[parentId]) { 
 
     temp[parentId] = { 
 
     category_id: parentId, 
 
     parent_category_id: undefined, 
 
     title: undefined, 
 
     subcategories: [temp[inputArr[i].category_id]] 
 
     } 
 
    } else { 
 
     temp[parentId].subcategories = temp[parentId].subcategories || []; 
 
     temp[parentId].subcategories.push(temp[inputArr[i].category_id]); 
 
    } 
 
    } 
 
    
 
    delete temp[inputArr[i].category_id].parent_category_id; 
 
} 
 

 
temp = undefined; 
 

 
document.write('<code><pre>' + JSON.stringify(parent, null, 2) + '</pre></code>');