JavaScript Data Structure-list

Application Scenario: Shopping list

A list that does not contain any elements is called an empty list

The complete abstract data type definition for the list:

Listsize (attributes)	Number of elements in the list
POS (properties)	The current position of the list
Length (property)	Returns the number of elements in a list
Clear (method)	Empty all the elements in the list
ToString (method)	Returns the string form of the list
GetElement (method)	Returns the element at the current position
Insert (method)	Inserting a new element after an existing element
Append (method)	Add a new element at the end of the list
Remove (method)	Remove an element from the list
Front (method)	Moves the current position of a list to the first element
End (method)	Move the current position of the list to the last element
Prev (method)	Move the current position back one
Next (method)	Move the current position forward one
Currpos (method)	Returns the current position of the list
MoveTo (method)	Moves the current position to the specified position

Function list ()  {        this.listSize = 0;         this.append = append;         this.remove = remove;        this.pos =  0;        this.dataStore = [];         this.find = find;         this.tostring = tostring;        this.length =  length;        this.clear = clear;         this.insert = insert;         this.front = front;        this.end = end;         this.prev = prev;        this.next = next;         this.currPos = currPos;         this.moveTo = moveTo;         this.getelement = getelement;        this.contains =  contains;      }      function append ( Element)  {        this.dataStore[this.listSize++] =  Element;      }      function find (Element)  {        var dataStore = this.dataStore;         for (var i = 0, len = datastore.length;  i < len; i++) &nbsP {          if (datastore[i] == element)  {             return i;           }        }         return -1;      }       function remove (Element)  {        var fountat  = this.find (Element);         if (fountat > -1)  {          this.datastore.splice (fountAt, 1);           --this.listSize;           return true;        }         return false;      }      function  Length ()  {        return this.listSize;       }      function tostring ()  {         return this.dataStore;      }       function clear ()  {        delete  this.datastore;        this.datastore = [];         this.listSize = this.pos = 0;       }      function insert (Element, after)  {         var insertpos = this.find (after);         if (InseRTPOS&NBSP;&GT;&NBSP;-1)  {           This.dataStore.splice (insertpos + 1, 0, element); ++this.listsize;           return true;        }         return false;      }       function front ()  {         this.pos = 0;      }      function  End ()  {        this.pos = this.listSize - 1;       }      function prev ()  {         if (this.pos > 0)  {--this.pos;         }  &nBsp;   }      function next ()  {         if (this.pos < this.listsize - 1)  {++this.pos;         }      }       Function currpos ()  {        return this.pos;       }      function moveto (position)  {         this.pos = position;      }       function getelement ()  {         return this.dataStore[this.pos];      }       function contains (Element)  {        var  Datastore = thiS.datastore;        for (var i = 0, len =  datastore.length; i < len; i++)  {           if (datastore[i] == element)  {             return true;          }         }        return false;       }      var names = new  List ();       names.append ("1");       names.append ( "2");       names.append ("3");       names.append ("4 ");       names.append (" 5 ");       names.append (" 6 ") ;    &Nbsp;  names.insert ("7",  "6");       names.prev ();       console.log (Names.contains ("7"));

JavaScript Data Structure-list