JavaScript Object Properties Additions, deletions, JSON objects and string conversion methods, etc.

1: Adding object properties dynamically

var obj = new Object ();

Console.log (Obj.username);

Obj.username = "haha";

Console.log (Obj.username);

Undefined

haha

denoted by "[]". Written obj["username"] = "haha";

var obj = new Object ();

Console.log (Obj.username);

obj["username"] = "haha";

Console.log (Obj.username);

Undefined

haha

You can also define directly

var obj = {username: "haha", Password: "123"};

Console.log (Obj.username);

Console.log (Obj.password);

haha

123

2: Delete attribute , use Delete

var obj = new Object ();

obj["username"] = "haha";

Console.log (Obj.username);

Delete Obj.username;

Console.log (Obj.username);

haha

//undefined

3: Modify original property, add new attribute

var json = {

"Age": 24,

"Name": "Haha"

};

Modify The age value in Json

Json["age"] = 30;

Console.log (Json.age);

30

increase the sex value in Json

json["sex"] = "w";

Console.log (Json.sex);

W

4:json object and Json string Transfer

Json.parse (JSONSTR); you can convert a json string into a JSON object

var jsobj = {};
Jsobj.testarray = [n/a];
Jsobj.name = ' CSS3 ';
jsobj.date = ' 2017 ';
Console.log (Jsobj)
Console.log (typeof (Jsobj));
var str = json.stringify (jsobj);
var str1 = json.parse (str);
Console.log (str)
Console.log (typeof (str));
Console.log (STR1)
Console.log (typeof (STR1));
Object {testarray:array[3], name: "CSS3", Date: "2017"}
Object
{"Testarray": [[+], "name": "CSS3", "date": "2017"}
String
Object {testarray:array[3], name: "CSS3", Date: "2017"}
Object

Json.stringify (Jsonobj); you can convert a JSON object into a json string

var jsobj = {};
Jsobj.testarray = [n/a];
Jsobj.name = ' CSS3 ';
jsobj.date = ' 2017 ';
Console.log (Jsobj)
Console.log (typeof (Jsobj));
var str = json.stringify (jsobj);
Console.log (str)
Console.log (typeof (str));
Object {testarray:array[3], name: "CSS3", Date: "2017"}
Object
{"Testarray": [[+], "name": "CSS3", "date": "2017"}
String

JavaScript Object Properties Additions, deletions, JSON objects and string conversion methods, etc.