Question

我一直无法找到解决问题的正确方法。我想遍历嵌套的Products数组以显示每个产品名称。是否可以用我所写的内容，或者我是否需要以允许我更容易查询我需要的方式重新编写它？

            [
               {
                  "category":"A",
                  "products":[
                   {
                     "id":1,
                     "name":"Product 1",
                     "description":"Description of my product 1."
                   },
                   {
                     "id":2,
                     "name":"Product 2",
                     "description":"Description of my product 2."
                   },
                   {
                     "id":3,
                     "name":"Product 3",
                     "description":"Description of my product 3."
                   }
                  ]
               },
               {
                  "category":"B",
                  "products":[
                   {
                     "id":4,
                     "name":"Product 4",
                     "description":"Description of my product 4 in cat B."
                   },
                   {
                     "id":5,
                     "name":"Product 5",
                     "description":"Description of my product 5 in cat B."
                   },
                   {
                     "id":6,
                     "name":"Product 6",
                     "description":"Description of my product 6 in cat B."
                   }
                  ]
               }
            ]

Answer 1

假设整个结构位于名为data的变量中：

data.forEach(function(category) {
    if (category.hasOwnProperty('product')) {
        category.products.forEach(function(product) {
            console.log(product.name);
        });
    }
});

外部forEach循环遍历所有类别对象。内部forEach循环遍历每个类别中的所有产品对象。

Answer 2

通常，循环遍历数组things = [...]的方法如下：

for( var i=0; i<thing.length; i++ ) {
    // do stuff with thing[i]
}

循环遍历对象things = {...}就像这样：

for( key in things ) {
    if( things.hasOwnProperty(key) ) {
        // do stuff with things[key] or key.
    }
}

你可以随心所欲地嵌套它们。

在您的情况下，如果我们将原始数据结构命名为items，那么（见http://jsfiddle.net/7yc5arLe/）：

for( item=0; item<items.length; item++ ) {
    console.log('category is '+items[item].category);
    for( product=0; product<items[item].products.length; product++ ) {
        p = items[item].products[product];
        for( key in p ) {
            console.log('  product '+key+' is '+items[item].products[product][key]);
        }
    }
}

将输出

category is A
  product id is 1
  product name is Product 1
  product description is Description of my product 1.
  product id is 2
  product name is Product 2
  product description is Description of my product 2.
  product id is 3
  product name is Product 3
  product description is Description of my product 3.
category is B
  product id is 4
  product name is Product 4
  product description is Description of my product 4 in cat B.
  product id is 5
  product name is Product 5
  product description is Description of my product 5 in cat B.
  product id is 6
  product name is Product 6
  product description is Description of my product 6 in cat B.

Answer 3

当然有可能。

循环遍历数组[]：

for (initialization; condition; update) {
    ...
}

循环对象{}：

for (variable in object) {
    if (object.hasOwnProperty(variable)) {
        ...
    }
}

JavaScript循环遍历多维JSON数组

3 个答案: