Solved

How to input a value for an integer variable

Posted on 2006-11-12
7
179 Views
Last Modified: 2010-03-31
Hi,
I want to have the user input length and width so that my program calculates area and perimeter of a rectangle. How do I write the input statements? Here is my code:

class Rectangle {
private int length;
private int width;

public Rectangle(int l, int w) {
length = l;
width = w;
}

public int calculateArea() {
return length * width;
}

public int calculatePerimeter() {
return (2 * length + 2 * width);
}

public static void main(String args[]) {
    int l,w,area,perimeter;
    System.out.println("Input length:");
    l = input.nextInt(); //????
    System.out.println("Input width:");
    w = input.nextInt();//????
    Rectangle rect = new Rectangle(l,w);
    area = rect.calculateArea();
    perimeter = rect.calculatePerimeter();
    System.out.println("The area of the rectangle is: ");
 
System.out.println(area);
System.out.println("The perimeter of the rectangle is: ");
System.out.println(perimeter);

}
}

Thank you.

0
Comment
Question by:aej1973
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3
7 Comments
 
LVL 13

Expert Comment

by:kawas
ID: 17927365

quoting: http://javaalmanac.com/egs/java.io/ReadFromStdIn.html

e34. Reading Text from Standard Input

    try {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        String str = "";
        while (str != null) {
            System.out.print("> prompt ");
            str = in.readLine();
            process(str);
        }
    } catch (IOException e) {
    }
0
 
LVL 13

Expert Comment

by:kawas
ID: 17927372
the method process(str) would be the place that you would do something like:

try {
len = Integer.parseInt(str) ;
} catch (Exception e) {
// bad input
}
0
 

Author Comment

by:aej1973
ID: 17927425
Do I have to include or import any files to use the above code?
0
Online Training Solution

Drastically shorten your training time with WalkMe's advanced online training solution that Guides your trainees to action. Forget about retraining and skyrocket knowledge retention rates.

 
LVL 13

Expert Comment

by:kawas
ID: 17927430
java.io.BufferedReader
java.io.InputStreamReader
0
 

Author Comment

by:aej1973
ID: 17927449
This is my code. Where am I going wrong?

import java.io.BufferedReader;
import java.io.InputStreamReader;

class Rectangle {
private int length;
private int width;
public Rectangle(int l, int w) {
length = l;
width = w;
}
public int calculateArea() {
return length * width;
}
public int calculatePerimeter() {
return (2 * length + 2 * width);
}
public static void main(String args[]) {
    int l,w,area,perimeter;
    System.out.println("Input length:");
    try {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        String str = "";
        while (str != null) {
            System.out.print("> prompt ");
            str = in.readLine();
            process(str);
        }
    } catch (IOException e) {
    }

    System.out.println("Input width:");
    Rectangle rect = new Rectangle(l,w);
        area = rect.calculateArea();
        perimeter = rect.calculatePerimeter();
        System.out.println("The area of the rectangle is: ");
       
System.out.println(area);
System.out.println("The perimeter of the rectangle is: ");
System.out.println(perimeter);

}
}

0
 
LVL 13

Accepted Solution

by:
marchent earned 75 total points
ID: 17928243
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;

class Rectangle {
private int length;
private int width;
public Rectangle(int l, int w) {
length = l;
width = w;
}
public int calculateArea() {
return length * width;
}
public int calculatePerimeter() {
return (2 * length + 2 * width);
}
public static void main(String args[]) {
    int l,w,area,perimeter;
    try {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        System.out.print("Input Length : ");
        l = Integer.parseInt(in.readLine());
        System.out.print("Input width : ");
        w = Integer.parseInt(in.readLine());
        Rectangle rect = new Rectangle(l,w);
        area = rect.calculateArea();
        perimeter = rect.calculatePerimeter();
        System.out.println("The area of the Rectangle is : "+area);
        System.out.println("The perimeter of the Rectangle is : "+perimeter);
       
    } catch (Exception e) {
        System.out.println(e);
    }
}
}
0
 

Author Comment

by:aej1973
ID: 17929412
Thank you.
0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

By the end of 1980s, object oriented programming using languages like C++, Simula69 and ObjectPascal gained momentum. It looked like programmers finally found the perfect language. C++ successfully combined the object oriented principles of Simula w…
This was posted to the Netbeans forum a Feb, 2010 and I also sent it to Verisign. Who didn't help much in my struggles to get my application signed. ------------------------- Start The idea here is to target your cell phones with the correct…
Viewers learn how to read error messages and identify possible mistakes that could cause hours of frustration. Coding is as much about debugging your code as it is about writing it. Define Error Message: Line Numbers: Type of Error: Break Down…
This tutorial covers a practical example of lazy loading technique and early loading technique in a Singleton Design Pattern.
Suggested Courses

752 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question