;; Constants (define COOKIES .) ;; =============================================

Question

;; Constants
(define COOKIES .)

;; ======================================================================
;; Data Definitions

;; Natural is one of:
;; - 0
;; - (add1 Natural)
;; interp. a natural number
(define N0 0) ;0
(define N1 (add1 N0)) ;1
(define N2 (add1 N1)) ;2

#;
(define (fn-for-natural n)
(cond [(zero? n) (...)]
[else
(... n ; n is added because it's often useful   
(fn-for-natural (sub1 n)))]))

;; Template rules used:
;; - one-of: two cases
;; - atomic distinct: 0
;; - compound: 2 fields
;; - self-reference: (sub1 n) is Natural

;; ==========
;; Functions

;; Natural Image -> Image
;; produce an n-tall, n-wide pyramid of the given image
(check-expect (pyramid 0 COOKIES) empty-image)
(check-expect (pyramid 1 COOKIES) COOKIES)
(check-expect (pyramid 3 COOKIES)
(above COOKIES
(beside COOKIES COOKIES)
(beside COOKIES COOKIES COOKIES)))

(define (pyramid n i) empty-image) ; stub

Explanation / Answer

A message given to a Web browser by a Web server. The browser stores the message in a text file. The message is then sent back to the server each time the browser requests a page from the server.

Also see session cookie and persistent cookie.

The main purpose of cookies is to identify users and possibly prepare customized Web pages for them. When you enter a Web siteusing cookies, you may be asked to fill out a form providing such information as your name and interests. This information is packaged into a cookie and sent to your Web browser which stores it for later use. The next time you go to the same Web site, your browser will send the cookie to the Web server. The server can use this information to present you with custom Web pages. So, for example, instead of seeing just a generic welcome page you might see a welcome page with your name on it.

import java.io.*;  

import javax.servlet.*;  

import javax.servlet.http.*;    

public class FirstServlet extends HttpServlet {  

  public void doPost(HttpServletRequest request, HttpServletResponse response){  

    try{  

    response.setContentType("text/html");  

    PrintWriter out = response.getWriter();  

   String n=request.getParameter("userName");  

    out.print("Welcome "+n);  

    Cookie ck=new Cookie("uname",n);//creating cookie object  

    response.addCookie(ck);//adding cookie in the response  

    //creating submit button  

    out.print("<form action='servlet2'>");  

   out.print("<input type='submit' value='go'>");  

    out.print("</form>");  

              out.close();  

       }catch(Exception e){System.out.println(e);}    }  

1.    }

The name cookie derives from UNIX objects called magic cookies. These are tokensthat are attached to a user or program and change depending on the areas entered by the user or program.

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.