Question

I'm working on a java program where I'm supposed to convert 4 bit binary into decimal. I went with if statements and tried to use an else to print out an error message if the user enters a number that isn't a binary number but it prints no matter what. (so, it prints that it's a vowel and that it's not a vowel)

1 import java.util.Scanner;
2
3 public class HomeworkTwoQ2
4 {
5
6 public static void main(String[] args)
7 {
8
9 System.out.println("Please enter a four bit binary number: ");
10
11 Scanner binary = new Scanner(System.in);
12
13 int binaryInput = binary.nextInt();
14
15 if (binaryInput == 0000)
16 {
17 System.out.println("0");
18 }
19 if (binaryInput == 0001)
20 {
21 System.out.println("1");
22 }
23 if (binaryInput == 0010)
24 {
25 System.out.println("2");
26 }
27 if (binaryInput == 0011)
28 {
29 System.out.println("3");
30 }
31 if (binaryInput == 0100)
32 {
33 System.out.println("4");
34 }
35 if (binaryInput == 0101)
36 {
37 System.out.println("5");
38 }
39 if (binaryInput == 0110)
40 {
41 System.out.println("6");
42 }
43 if (binaryInput == 0111)
44 {
45 System.out.println("7");
46 }
47 if (binaryInput == 1000)
48 {
49 System.out.println("8");
50 }
51 if (binaryInput == 1001)
52 {
53 System.out.println("9");
54 }
55 if (binaryInput == 1010)
56 {
57 System.out.println("10");
58 }
59 if (binaryInput == 1011)
60 {
61 System.out.println("11");
62 }
63 if (binaryInput == 1100)
64 {
65 System.out.println("12");
66 }
67 if (binaryInput == 1101)
68 {
69 System.out.println("13");
70 }
71 if (binaryInput == 1110)
72 {
73 System.out.println("14");
74 }
75 if (binaryInput == 1111)
76 {
77 System.out.println("15");
78 }
79 else
80 {
81 System.out.println("Not a four digit binary number, exiting.");
82 }
83
84 }
85 }

Answer 1

// Screenshot of the code & output

// Code to copy

HomeworkTwoQ2.java

import java.util.Scanner;
public class HomeworkTwoQ2 {

   public static void main(String[] args) {
       System.out.println("Please enter a four bit binary number: ");
       Scanner binary = new Scanner(System.in);
       int binaryInput = binary.nextInt();
       if (binaryInput == 0000)
       {
           System.out.println("0");
       }else if(binaryInput == 0001) {
           System.out.println("1");
       }else if(binaryInput == 0010) {
           System.out.println("2");
       }else if(binaryInput == 0011) {
           System.out.println("3");
       }else if(binaryInput == 0100) {
           System.out.println("4");
       }else if(binaryInput == 0101) {
           System.out.println("5");          
       }else if(binaryInput == 0110) {
           System.out.println("6");
       }else if(binaryInput == 0111) {
           System.out.println("7");
       }else if(binaryInput == 1000) {
           System.out.println("8");
       }else if(binaryInput == 1001) {
           System.out.println("9");
       }else if(binaryInput == 1010) {
           System.out.println("10");
       }else if(binaryInput == 1011) {
           System.out.println("11");
       }else if(binaryInput == 1100) {
           System.out.println("12");
       }else if(binaryInput == 1101) {
           System.out.println("13");
       }else if(binaryInput == 1110) {
           System.out.println("14");
       }else if(binaryInput == 1111) {
           System.out.println("15");
       }else {
           System.out.println("Not a four digit binary number, exiting.");
       }
       binary.close();
   }

}