CODEWITHSUNDEEP
javaeclipse
Zwiebel
Zwiebel

Reputation: 1615

What's the problem with this code in Java?

I want to make a program in Java in Eclipse, what tell me, if I can make the triangle or not. It is my code:

import java.io.IOException;

public class haromszog {
    public static void main(String[] args) throws IOException {

        int a;
        int b;
        int c;

    System.out.print("Please insert the 'a' side of the triangle:");
    a = System.in.read();

    System.out.print("Please insert the 'b' side of the triangle:");
    b = System.in.read();

    System.out.print("Please insert the 'c' side of the triangle:");
    c = System.in.read();

    if ((a+b)>c)
    {
        if ((a+c)>b)
        {
            if ((b+c)>a)
            {System.out.print("You can make this triangle");
            }
            else 
                System.out.print("You can't make this triangle");

        }
    }
    }
}

The Eclipse, can run it, but it writes:

Please insert the 'a' side of the triangle: (for example I write: ) 5

Please insert the 'b' side of the triangle:

Please insert the 'c' side of the triangle:

You can't make this triangle

And I can't write anything to the b and c side. What's the problem with this?

Upvotes: 0

Views: 347

Answers (5)

Amir Afghani
Amir Afghani

Reputation: 38531

Adding to Joachim's answer, try this:

import java.io.IOException;
import java.util.Scanner;

public class foo {
    public static void main(String[] args) throws IOException {

    Scanner s = new Scanner(System.in);

    System.out.print("Please insert the 'a' side of the triangle:");
    int a = s.nextInt();

    System.out.print("Please insert the 'b' side of the triangle:");
    int b = s.nextInt();

    System.out.print("Please insert the 'c' side of the triangle:");
    int c = s.nextInt();

    }
}

Upvotes: 1

user unknown
user unknown

Reputation: 36229

You read a byte, so if it is the ascii-charcter '5' it is not the number 5, but 53. Your next problem is Carriage-Return which is read as the next byte.

Use the java.util.Scanner class instead:

Scanner sc = new Scanner (System.in);
int a = sc.nextInt ();

Upvotes: 1

Kaleb Brasee
Kaleb Brasee

Reputation: 51935

In addition to the System.in.read() problem, you need to combine your if statements, because that the else clause currently only applies to the inner one.

if ((a+b)>c && (a+c)>b && (b+c)>a) { 
   System.out.print("You can make this triangle");
}
else {
   System.out.print("You can't make this triangle");
}

Upvotes: 2

Andrey
Andrey

Reputation: 60065

From http://download.oracle.com/javase/1.4.2/docs/api/java/io/InputStream.html:

read() : Reads the next byte of data from the input stream.

You read not integer, but char code.

You should probably do:

java.util.Scanner s = new java.util.Scanner(System.in); 
int k = s.nextInt();

Upvotes: 5

Joachim Sauer
Joachim Sauer

Reputation: 308021

System.in.read() reads a single byte from standard input of your application. That's almost certainly not what you want (unless something is passing binary data to your application).

You could try System.console().readLine() instead (followed by Integer.parseInt() to convert the resulting String to an int).

Upvotes: 8

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