List of JavaScript data structure lists

I. Summary of Prerequisites

In the normal development of JavaScript programs, the display of the list data is often used. For example: Heat list, headline list, achievement list, to-do items, and so on, the above data have some common characteristics, the data structure is simple, the amount of data is small. Then, based on the above characteristics, to customize a list class, only need to encapsulate a few queries, positioning and other methods can help us to deal with the data. Of course, once the data structure is very complex, and the amount is larger, the role of the list class is not that big.

Second, data abstraction

1. Attribute definitions:

Property	Note
DataSource	stored data sources for lists
Size	The length and number of the list
Position	The current index position of the list

　　

2. Method definition:

Method	Note
Append	adding elements
Insert	Insert element (Specify position insertion)
Remove	Delete Element
Clear	Clear List
Find	Querying elements
Get	Get element
First	Gets the first element
Last	Gets the last element
Prev	Move to previous position
Next	Move to the next position
Front	Move to start position
End	Move to end position
Hasprev	Whether there is a previous element
Hasnext	Whether there is a later element
MoveTo	Move to the specified position
Length	Returns the length of the list
Contains	Whether to include the specified element
Tostring	Return Data source DataSource

The above data structure is defined according to the actual requirement, and the different usage environment can be modified accordingly.

Third, the code implementation

1 //List Class2 varList =function () {3     //Data Source4      This. DataSource = [];5     //Data Length6      This. Size = 0;7     //Current Position8      This. Position = 0;9 };Ten  OneList.prototype.constructor =List; A  -List.prototype = { -     //adding elements theAppendfunction(Element) { -          This. datasource[ This. size++] =element; -     }, -     //inserting elements +Insertfunction(position, Element) { -         if(Position >-1) { +              This. Datasource.splice (position + 1, 0, Element); A              This. size++; at             return true; -         } -         return false; -     }, -     //remove Element -Removefunction(position) { in          This. Datasource.splice (Position, 1); -     }, to     //Clear Data Source +Clearfunction () { -         Delete  This. DataSource; the          This. datasource.length = 0; *          This. Size = 0; $          This. Position = 0;Panax Notoginseng     }, -     //Querying Data theFindfunction(Element) { +          for(vari = 0; I < This. datasource.length; i++) { A             if( This. datasource[i] = =Element) { the                 returni; +             } -         } $         return-1; $     }, -     //Get Data -Getfunction () { the         return  This. datasource[ This. position]; -     },Wuyi     //get the first piece of data theFirstfunction () { -         return  This. datasource[0]; Wu     }, -     //get the last piece of data AboutLastfunction () { $         return  This. datasource[ This. size-1]; -     }, -     //move to previous position -Prevfunction () { A          This. position--; +     }, the     //move to the next position -Nextfunction () { $          This. position++; the     }, the     //move to start position theFrontfunction () { the          This. Position = 0; -     }, in     //move to end position theEndfunction () { the          This. Position = This. size-1; About     }, the     //whether there is a previous element theHasprev:function () { the         return  This. position > 0; +     }, -     //whether there is a later element theHasnext:function () {Bayi         return  This. Position < This. size-1; the     }, the     //move to the specified position -MoveTo:function(position) { -          This. Position =position; the     }, the     //Data Source Length theLengthfunction () { the         return  This. Size; -     }, the     //whether to include the specified element theContainsfunction(Element) { the          for(vari = 0; I < This. datasource.length; i++) {94             if( This. datasource[i] = =Element) { the                 return true; the             } the         }98         return false; About     }, -Tostring:function () {101         return  This. DataSource;102     }103};

Iv. Demonstration of examples

1 varList =NewList ();2List.append ("Zhang San");3List.append ("John Doe");4List.append ("Harry");5List.append ("Zhao Liu");6Console.log ("list dataSource, size, Position:", List.datasource, List.size, list.position);7 //Print: List dataSource, size, Position: ["Zhang San", "John Doe", "Harry", "Zhao Liu"] 4 08 9Console.log ("List Get ():", List.get ());Ten //Print: List get (): Zhang San One  A List.next (); -Console.log ("List prev ():", List.get ()); - //Printed: List prev (): John Doe the  -List.moveto (3); -Console.log ("List moveTo ():", List.get ()); - //Printed: List MoveTo (): Zhao Liu +  - varPosition = List.find ("Harry"); +Console.log ("List find ():", position); A //Printing: List Find (): 2 at  - varresult = List.contains ("Cao Qi"); -Console.log ("list contains ():", result); - //Printed: List contains (): false

List of JavaScript data structure lists