Question

Module 4 follow the materials available at Topic - Stacks and Queues. You should have a good understanding of Lists at  Topic - Basic Data structures as a Queue and a Stack are simply implementation of a List with specific properties.

Assignment - Implement a Stack computer in Javascript (you will turn in a link to your program in JSFiddle). This is a simple computer that keeps a stack, when a number is entered it goes onto the top of the stack. When an operation is entered, the previous 2 numbers are operated on by the operation.

For example:

2 [enter] 2

5 [enter]   5 2

* [enter] * 5 2 -> collapses to 10

would leave at 10 at the top of the stack.

The program should use a simple input box, either a text field or prompt and display the contents of the Stack.

Answer 1

this.peek-function ) return items[items.length-11 this.isEmpty- function () return items.length0; //Allocating size for array// this.size- function) return items.length; this.clear-function ) items [

this.print -function0 alert ("myStack Elements are: "titems.toString ()).; //Decalration of the myStack object// var myStack new mys tack() ; //loop started// while (1)

//stack operation// myStack.push(element) myStack.print alert ("Great Full! "

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he page at hmps/fiddleishelnet says Login Sign up1 tack Eements are24 OK thot a JSFIDDLE . SFIDDLE The page at hsdl shellnet says Lagin'Sign p ter stack elementi orQto Pirevent ths page fomceating additional aliog

SFIDOLE The page at https//Sddle jshell.net says

JSFOOLE The page at https//iddlejshellnet says

//Class function decleration//

function myStack()

     {

          var items = [];

          //Push function//

          this.push = function(element){

          items.push(element);

     };

     //pop function//

this.pop = function()

     {

          return items.pop();

     };

this.peek = function()

     {

          return items[items.length-1];

     };

this.isEmpty = function()

     {

          return items.length == 0;

     };

     //Allocating size for array//

this.size = function()

     {

          return items.length;

     };

this.clear = function()

     {

          items = [];

     };

this.print = function()

     {

          alert("myStack Elements are:"+items.toString());

     };

}

//Decalration of the myStack object//

var myStack = new myStack();

//loop started//

while(1)

     {

          var element = prompt("Enter myStack element,(q or Q to exit)", "");

          //Condition//

          if(element == 'q' || element =='Q')

              {

                   break;

              }

          else

              {

              if(element=='*'|| element=='+' || element=='-' || element=='/')

                   {

                        //ensure if myStack is empty

                        if(myStack.isEmpty() || myStack.size<2 )

                             {

                                  alert("Invalid process, myStack is empty() or size is less than 2");

                             }  

                        else

                             {

                                  var op1 = myStack.pop();

                                  var op2 = myStack.pop();

                                  if(element=='*')

              {

                   var res = op1 * op2;

              }

     else if(element=='+')

          {

              var res = op1 + op2;

          }

     else if(element=='-')

          {

              var res = op1 - op2;

          }

     else if(element=='/')

          {

              var res = op1 / op2;

          }

     myStack.push(res);

     myStack.print();

          }   

}

else

     {

          //Stack operation//

          myStack.push(element);

          myStack.print();

     }

}

}  

alert("Great Full!");