Detailed explanation of the use of {}, [] square brackets and curly brackets in js_javascript skills

1. { } curly brackets indicate the definition of an object. In most cases, it must have paired attributes and values, or functions.
For example: var LangShen = {"Name":"Langshen","AGE":"28"};
The above declares an object named "LangShen", multiple properties or functions are , (comma) separated, because it is an attribute of the object,
, so when accessing, you should use . (dot) to access layer by layer: LangShen.Name, LangShen.AGE. Of course, we can also use arrays to access, For example: LangShen["Name"], LangShen["AGE"], the results are the same.
This writing method is often used in JSON data structures. In addition, we often use it when we write function groups, such as:

Copy Code The code is as follows:

var LangShen = {
Name = function(){
return "LangShen";
},
Age = function(){
return "28";
}
}

The calling method is similar. Because it is a function group, () must be added, such as: alert( LangShen.Name() );
2. [ ] brackets represent an array, which can also be understood as an array object.
For example: var LangShen = [ "Name", "LangShen", "AGE", "28" ];
Obviously, each value or function is independent. Only separated by, (comma), because it is an array object, so it is equal to:
var LangShen = Array( "Name", "LangShen", "AGE", "28" );
When accessing, It is also the same as an array, alert( LangShen[0] );
3. { } and [ ] are used together. As we mentioned earlier, { } is an object and [ ] is an array. We can form an Object array, such as:

Copy code The code is as follows:

var LangShen = { "Name":"Langshen",
"MyWife":[ "LuLu","26" ],
"MySon":[{"Name":"Son1"},{"Name":"Son2 "},{"Name":"Son3"}]
}

From the above structure, the first item in an object is an attribute, and the second item is an array , and the third one is an array containing multiple objects. When called, it is also accessed layer by layer. The properties of the object are superimposed with . (dot), and the array is accessed with [subscript].
For example: alert(LangShen.MySon[1].Name);