JavaScript在多维JSON数组中循环

JavaScript looping through multimensional JSON arrays

本文关键字：数组 循环 JSON JavaScript      更新时间：2023-09-26

我一直无法找到我的问题的正确解决方案。我想循环遍历嵌套的Products数组以显示每个Product名称。我写的东西有可能吗，或者我需要重新写一遍，让我更容易查询我需要的东西吗?

            [
               {
                  "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."
                   }
                  ]
               }
            ]

假设整个结构位于一个名为data的变量中:

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

外层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。

一般来说，循环遍历数组things = [...]是这样完成的:

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

对象things = {...}的循环是这样完成的:

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。

在你的例子中，如果我们将你的原始数据结构命名为items，那么(参见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.

当然可以。

  • 循环遍历数组[]:

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

  • 遍历对象{}:

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