Question

如何在jsp中创建json对象？

var jsonObj = {
    "firstname": "test",
    "lastName": "test",
    "email": "test",
    "mobile": "test",
    "place": "test",
    "country": "test"
};

alert(jsonObj.length);

这会打印“未定义”的长度。

var json = {"person":
    {
        "p1":
            {"home":
                {"address":0,
                "phoneNumber":0
                },
            "office":
                {"address":0,
                "phoneNumber":0
                }
            },

        "p2":
            {"home":
                {"address":0,
                "phoneNumber":0
                },
            "office":
                {"address":0,
                "phoneNumber":0
                }
            },

        "p3":
            {"home":
                {"address":0,
                "phoneNumber":0
                },
            "office":
                {"address":0,
                "phoneNumber":0
                }
            },
    },

    "msg":"People data"
} ;

假设这是我的json对象。我想运行循环并遍历值..

alert("json length = " + Object.keys( json ).length);   //2
alert("keys in json : " + Object.keys(json));   //person,msg

var people = json.person;   
var personLen = Object.keys( people ).length;   //3

现在我想运行一个循环并获取p1，p2，p3 ..

中的值

for(i=0; i<people; i++) {

    var person = people[i]; //but this doesnt work

}

如何使用循环获取这些值？

Answer 1

这打印＆＃34; undefined＆＃34;长度。

因为它没有名为length的属性，并且它不是具有内置属性length的数组。

如果要获取此对象中的属性数，请尝试

Object.keys( jsonObj ).length

Answer 2

对象

上没有长度属性

var jsonObj = {
    "firstname": "test",
    "lastName": "test",
    "email": "test",
    "mobile": "test",
    "place": "test",
    "country": "test"
};
// It will return an array of 6   elements['test','test','test','test','test','test']
var a =Object.keys(jsonObj) 
alert(a.length);

JSFIDDLE

如何在jsp中创建json对象？

2 个答案: