Write a Program Area of Rectangle in Java- Technology369kk

 Area of Rectangle: 

In this post we are discussing  about area of rectangle using java programming language, I'm just suggest you pls create a file of java and run class file in cmd runner . 

Program:   

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.*;  //All in one

class AreaR{

    public static void main(String[] args){

        int width = 0;

        int length = 0;

   

    try {

        // read the length from console

            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

            System.out.print("Please enter length of a rectangle: -");

            width = Integer.parseInt(br.readLine());

            System.out.print("Please enter width of a rectangle: -");

            length = Integer.parseInt(br.readLine());

    }

    // if Invailed value was entered

    catch(NumberFormatException ne){

            System.out.println("Invailed value" + ne);

            System.exit(0);

    }

    catch(IOException ioe){

            System.out.println("IO Error: "+ ioe);

            System.exit(0);

    }

        int area = length*width;

        System.out.println("Area of Rectangle value is:" + area);

    }

}

Explanations Program:  

1. Import Statements

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

• BufferedReader and InputStreamReader:
• Used for reading input from the console. 
• IOException:
• Handles input/output errors. 
• NumberFromatException:
• Handles error if a non-integer value is entered. 

2. Variable Declaration: 

int width = 0;

int length = 0;

   

• width and length:
• Store the dimensions of the rectangle, initialized to 0. 

3. Reading User Input 

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

System.out.print("Please enter length of a rectangle: -");

width = Integer.parseInt(br.readLine());

System.out.print("Please enter width of a rectangle: -");

length = Integer.parseInt(br.readLine());

• BufferedReader and InputStreamReader:
• Create a pipeline to read user input from the console.
• System.out.print:
• Prompts the user to enter the rectangle's length and width.
• Integer.pareInt(): 
• Converts the string input (from br.readLine()) into an integer.

4. Error Hanfling(Try-Catch Block)

The program uses two catch blocks to handle exceptions:

a. catch(NumberFormateException  ne)

catch(NumberFormatException ne){

            System.out.println("Invailed value" + ne);

            System.exit(0);

    }

Triggered if the user enters a non-numeric value.

Prints an error message: "Invalid value" and exits the program.

b. catch(IOException ioe)  

catch(IOException ioe){

            System.out.println("IO Error: "+ ioe);

            System.exit(0);

    }

• Triggered if an I/O error occurs while reading input.
• Prints "IO Error" and exits the program.

5. Calculate and Print the Area

int area = length*width;

System.out.println("Area of Rectangle value is:" + area);

area = length * width;:

• Computes the rectangle's area.

System.out.println:

• Displays the calculated area.

OUTPUT

PS D:\Learning File\BCA\BCA 3rd Sem\JAVA OOP\AllPraQue> java AreaR  

Please enter length of a rectangle: -5

Please enter width of a rectangle: -10

Area of Rectangle value is:50

Key Points:

1. Exception Handling:

   • Prevents the program from crashing due to invalid user input.

2. BufferedReader:

   • Efficient way to read console input as strings.

3. Type Conversion:

   • Converts user input from string to integer using Integer.parseInt().

4. Multiplication Logic:

• Calculates the area using the formula length * width.

I hope