读取嵌套对象

Question

我有一个像这样的对象

var JSON_Object = {
"Diabites": [
    {
        "Day1": [
            {
                "Breakfast": [
                    {
                        "food1": "Bread",
                        "food2": "Tea",
                        "food3": "Edd"
                    }
                ]
            },
            {
                "Lunch": [
                    {
                        "food1": "Bread",
                        "food2": "Tea",
                        "food3": "Edd"
                    }
                ]
            },
            {
                "Dinner": [
                    {
                        "food1": "Bread",
                        "food2": "Tea",
                        "food3": "Edd"
                    }
                ]
            }
        ]
    },
    {
        "Day2": [
            {
                "Breakfast": [
                    {
                        "food1": "Bread",
                        "food2": "Tea",
                        "food3": "Edd"
                    }
                ]
            },
            {
                "Lunch": [
                    {
                        "food1": "Bread",
                        "food2": "Tea",
                        "food3": "Edd"
                    }
                ]
            },
            {
                "Dinner": [
                    {
                        "food1": "Bread",
                        "food2": "Tea",
                        "food3": "Edd"
                    }
                ]
            }
        ]
    }
]
}

现在我如何使用一些循环打印出来读取此文件。我尝试了以下

alert(JSON_Object.Diabites.length); // Return 1 
alert(JSON_Object.Diabites[0].Day1.length); // Return 3

但是有Day1, Day2, Day3 ....等不同的名称，所以如何在循环中更改该部分，如

for(var i=0; i<JSON_Object.Diabites.length;i++)
{
    alert(JSON_Object.Diabites[i].Day1.length);
}

更新JSON对象

var JSON_Object = {
"Diabites": [
    {
        "Day1": [
            {
                "Breakfast": [
                    {
                        "food1": "Bread"
                    },
                    {
                        "food2": "Tea"
                    },
                    {
                        "food3": "Edd"
                    }
                ]
            },
            {
                "Lunch": [
                    {
                        "food1": "Bread"
                    },
                    {
                        "food2": "Tea"
                    },
                    {
                        "food3": "Edd"
                    }
                ]
            },
            {
                "Dinner": [
                    {
                        "food1": "Bread"
                    },
                    {
                        "food2": "Tea"
                    },
                    {
                        "food3": "Edd"
                    }
                ]
            }
        ]
    },
    {
        "Day2": [
            {
                "Breakfast": [
                    {
                        "food1": "Bread"
                    },
                    {
                        "food2": "Tea"
                    },
                    {
                        "food3": "Edd"
                    }
                ]
            },
            {
                "Lunch": [
                    {
                        "food1": "Bread"
                    },
                    {
                        "food2": "Tea"
                    },
                    {
                        "food3": "Edd"
                    }
                ]
            },
            {
                "Dinner": [
                    {
                        "food1": "Bread"
                    },
                    {
                        "food2": "Tea"
                    },
                    {
                        "food3": "Edd"
                    }
                ]
            }
        ]
    }
]
};

Answer 1

如果你想循环json的键，你可以这样做

for(var key in JSON_Object.Diabites[0]){

  //key will be Day1,Day2 etc.
  alert(JSON_Object.Diabites[0][key].length);

}

但是在你的json结构中，你必须使用

for(var i=0;i<JSON_Object.Diabites.length;i++) {

    for(var key in JSON_Object.Diabites[i]) {

      //key will be Day1,Day2 etc.
      alert(key);
      alert(JSON_Object.Diabites[i][key].length);

    }

}

here is a working fiddle如果您有兴趣。