Summary of several methods of declaring objects under JavaScript_javascript skills

1.var myObject = {};
2.function myObject()
{
....
}
3.var myObject = function(){};
For For the latter two methods, we can also add parameters, which is similar to a constructor with parameters.
For example:
function myObject(msg)
{
alert(msg) ;
}
var newObject = new myObject('Hello, World!') ;


var myObject = function(msg)
{
alert(msg 'again') ;
}
var newTwoObject = new myObject('Hello, World!);


Even we can use strings to declare functions, which makes our program more flexible
For example :
var myObject = new Function("msg","alert(msg)") ;
// Function can have multiple entry parameters, and the last parameter is used as the method body.
var newObject = new myObject('Hell, World!);

Declaration of members in JavaScript
In JavaScript, it is very simple to declare the members of an object, but unlike other advanced programs Still slightly different
For example:
var myObject = {
"FirstName" : "thtwin",
"LastName" : "thtwinj2ee",
"Age" : 22,
"showFullName" : function()
{
alert(this.FirstName ' ' this.LastName) ;
}

} ;
myObject.showFullName() ;

Another object-oriented feature in JavaScript is that we can use . and [] reference members like a high-level programming language.
For example:
var dateTime = {
now : new Date(),
show : function(){
alert(new Date()) ;
}
} ;
alert(dateTime.now) ;
Equivalent to:
alert (dateTime.now) ;

dataTime.show() ;
is equivalent to:
dateTime["show()"] ;

for method calls, in In JavaScript, the base class of all objects is Object. The base class defines many members
and methods through prototype, such as: toString, toLocaleString, etc.
For example:
var obj = {"toString": function(){return "This is an test!" ; }} ;
alert(obj) ;

When running, the toString() method is called when alert occurs. In fact, when JavaScript When an object needs to be converted into a character
, the object's toString() method is implicitly called.
For example:
Date.prototype.toString = function(){alert('this is a test! ') ;} ;
var da = new Date(new Date()) ;

Date.prototype.toString = function(){alert('this is a test!') ;} ;
var dt = new Date() 1;

Usage of call method in JavaScript:
Explanation about call:
The call method can be used to call a method instead of another object. The
call method changes the object context of a function from the initial context to the new object specified by thisObj.

For example:
function abc()
{
alert(this.member1);
}
var obj = { member1:"Hello world!", show: abc};
var obj2 = { member1:"Hello world again!", show:abc};

obj.show();
//You can also use
abc.call (obj);
abc.call(obj2);

Another modified version:
member1 = 'test';
function abc()
{
alert(this.member1);
}
var obj = { member1:"Hello world", show:abc};
var obj2 = { member1:"Hello world again", show:abc};

obj.show();
//You can also use
abc.call(obj);
abc.call(obj2);

abc(); // At this time, this in abc points to the current context
Each function has a call method. In the above process, we see that another object is used instead of calling the display method,
and notice that this is in the object context changes.